Commercialization Of Lithium Ion Batteries Research Articles

Applying nanomaterials to enhance the energy density of lithium-ion batteries

Abstract The technological improvement and commercialization of lithium-ion batteries have gone through a long period of development, and energy density is a crucial link in their development. At present, nanomaterials have made significant contributions to improving the energy density of batteries, while also effectively addressing some issues including safety and stability. Because of there will be some small size effects, such as an increase in conductivity, an enhancement of all mechanical, optical, and even superparamagnetic behaviour, when the size of the particles inside the material is reduced to match the wavelength of the electron, phonon, and Magnon. Scientists have also made targeted modifications to electrode and electrolyte materials based on these principles, using different technologies to improve the energy density and other electrochemical function of lithium-ion batteries. As a result, this research will start with the cathode, anode, and electrolyte materials of batteries, and explain the applications and principles of related nanomaterials.

Co-doping strategies for advanced solid state electrolytes with lithium salt: a study on the structural and electrochemical properties of LATP

The commercialization of lithium-ion batteries has revolutionized the field of energy storage, yet their usage of organic electrolytes has led to significant safety concerns. Solid-state electrolytes have emerged as a promising solution to these issues, enabling the development of high-performance solid-state lithium batteries. The NASICON-type solid electrolyte Li1.3Al0.3Ti1.7P3O12 (LATP) has demonstrated excellent properties and significant potential. This study involves the solid-state synthesis of LATP electrolytes doped with Cobalt and Silicon. Furthermore, adding 8% LiBr into LATP-0.04 significantly enhanced ionic conductivity, reaching a value of 3.50 × 10−4 S cm−1. This can be linked to lithium salt filling vacant spaces between grains, resulting in a significant drop in grain boundary resistances. The electrochemical analysis through Linear Sweep Voltammetry (LSV) indicates that the investigated material demonstrates the capability to sustain stability and functionality even under the influence of elevated voltages, notably up to 5.45 V. These findings imply that optimal cobalt doping and Lithium salt contribute to superior ionic conductivity compared to pristine LATP.

Scalable Pore Engineering Strategy for Promoting Ion Transport and Rate Capability in Thick Li-Ion Battery Electrodes

Since the first commercialization of lithium-ion batteries (LIBs) in the early 1990s, previous research has been extensive on electrode material development. Due to its high volumetric energy and power densities and its low cost, the LIBs have aided in the widespread adoption of advanced mobile electronic devices, slowly spurred the market penetration of electric vehicles (EVs) globally and been incorporated in household energy storage systems to promote efficient use of renewable energy1,2. Unfortunately, after rapid improvements in LIB technology, the present progress in increasing energy density and reducing the costs of LIBs has been slow. To overcome the performance limitations on the material side, increasing the nickel (Ni) content of layered lithium nickel cobalt aluminum oxide (NCA) and lithium nickel cobalt manganese oxide (NCM) cathode materials and blending silicon with graphite anode materials have shown promise3,4,5. On the manufacturing side, there is a push to use thicker and denser electrodes and increase areal capacity loadings from 3-4 mAh/cm2 to 5-7 mAh/cm2 to reduce the mass and volume fraction of inactive materials and thus reduce costs and improve the energy density and specific energy of LIB cells beyond about 700 Wh/L and 250 Wh/kg, respectively6.-8 . Unfortunately, the characteristic Li+ ion diffusion time is proportional to the square of the average diffusion path through the electrode, which depends on both the electrode thickness and the tortuosity. As a result, the charging time and power performance characteristics in high-loading, dense electrodes may become undesirably poor. Herein, we report on several manufacturing pathways to create straight channel pores within electrodes to accelerate electrolyte wetting and facilitate rapid ion transport to overcome these rate limitations.

(Invited) Flexible and Safe Zinc Alkaline Solid-State Rechargeable Battery for Wearable Applications

Wearable electronics are one of the most rapidly growing industries, due to their extended use in everyday applications resulting in an increased demand for portable energy storage devices. Despite immense success in commercialization of Lithium-ion batteries (LIBs), conventional LIBs suffer from issues of cost and safety. The expanding need for cheaper, and safer energy storage devices led explorations towards alternatives. After careful considerations, Zinc (Zn)-Manganese dioxide (MnO2) based alkaline system was chosen to be investigated in this work due to its low cost, inherent safety, and high theoretical energy density. However, challenges associated with making the aforementioned system rechargeable and highly performing still remains. The work in this study is directed towards enhancing the overall performance of the Zn-MnO2 alkaline battery in addition to making it suitable for flexible and wearable applications. A highly ionically conducting polymer electrolyte ({5}CP) with excellent physical and electrochemical stability primarily comprising biopolymer chitosan is prepared by using a time and energy-efficient technique. Incorporation of this polymer electrolyte with Zn anode and MnO2 cathode enabled the successful preparation of a physically flexible cell. To obtain high cyclability and performance of the system; issues of inactive phase formations (MnxOy, ZnMnxOy), low active material availability, pronounced shape changes at the anode surface, and zincate ion transfer towards cathode were overcome by enhancing the electrochemically active layers in the system. The assembled cell comprising the enhanced fabricated layers; (i.e. a Zinc/Stainless steel mesh composite anode, a hierarchical binder-free bismuth and copper additives based MnO2 cathode, and a chitosan-based polymer electrolyte with calcium hydroxide additive) indicated excellent rate capabilities (486 mAh/g @ 0.1 A/g, 78% of the theoretical 2-electron capacity on MnO2), long cycling stabilities (70% retention over 1000 cycles), and good energy densities (155 – 400 Wh/kg @ 0.1 – 1 A/g). Moreover, a number of destructive tests such as being bent, hammered, pressurized, and punctured were conducted on the pouch cell fabricated using the above-mentioned layers to analyze the cells’ safety, reliability, and robustness. Results indicated not much deterioration in capacities. Additionally, when the cell was bent and tested for long performance; a stable discharge capacity (270 mAh/g @ 1 A/g) was obtained after 250 cycles, thus attesting to excellent cycling stability. The successful working of the fabricated cell was validated by lighting up an LED. The successful findings presented in this study can chart new pathways to the development of safe, flexible, cost-effective, and more environmentally responsible alternative energy storage sources for wearables.

Research progress on solid polymer electrolytes

<p indent="0mm">Since the commercialization of lithium-ion batteries in the 1990s, lithium-ion batteries have been successfully applied in portable electronics, electric vehicles, and grid energy storage. Although current organic liquid electrolytes have high ionic conductivities, they are inherently flammable, volatile, and prone to leakage. Moreover, severe side reactions and dendrite growth on the surface of the lithium anode during the charge-discharge process can cause safety hazards, which greatly impede their applications in lithium metal batteries. Solid electrolytes, including inorganic solid electrolytes and polymer electrolytes, are regarded as effective alternatives to organic liquid electrolytes for the construction of lithium metal batteries with high energy density and safety. Among them, solid polymer electrolytes offer excellent flexibility, processability, and interfacial compatibility over inorganic solid electrolytes, and they are extraordinarily promising for lithium metal batteries with high energy density and safety. Ideal solid polymer electrolytes should have following features: (1) High ionic conductivity (&gt; <sc>10 ^–4 S cm ^–1) </sc> at room temperature; (2) high lithium ion transference number (~1) to reduce the concentration polarization and improve the rate performance of batteries; (3) intimate contact at the electrode/electrolyte interfaces; (4) wide electrochemical window <sc>(&gt;4.5 V</sc> vs. Li/Li ⁺) to match high-voltage cathodes and improve the energy density of batteries; (5) good mechanical stability to resist processing, buffer electrode volume change and inhibit dendrite growth; (6) good thermal stability to withstand environmental changes. Generally, the ionic conductivity of pure solid polymer electrolytes at room temperature is low <sc>(~10 ^–6 S cm ^–1). </sc> Researchers have tried to improve the ionic conductivities by adjusting the lithium salt concentration, such as developing “polymer-in-salt” solid electrolytes. However, increasing the concentration of lithium salt leads to the deterioration of the mechanical strength. Strategies such as developing novel lithium salts, modifying polymer matrix, and incorporating inorganic fillers into solid polymer electrolytes are proposed to promote ionic conductivities of solid polymer electrolytes. In particular, composite polymer electrolytes, fabricated by dispersing a certain amount of inorganic fillers into solid polymer electrolytes, have improved ionic conductivities without sacrificing their mechanical performances. Poor interfacial property between electrodes and electrolytes is also a critical issue for solid polymer electrolytes. On one hand, poor and uneven solid/solid contacts at the electrode/electrolyte interfaces lead to high resistance and sluggish ionic transport kinetics. Furthermore, the volume change of the positive and negative electrodes in the charge/discharge process deteriorates the interfacial contacts, blocks the ion and electron transport through the interfaces, and greatly reduces the electrochemical reaction kinetics. On the other hand, the electrochemical windows of solid polymer electrolytes are usually narrow <sc>(＜4.5 V).</sc> During cycling, redox reactions are prone to occur at the electrode/electrolyte interfaces, causing battery failure. Solid polymer electrolytes have also poor thermal and mechanical stabilities. Therefore, design and synthesis of polymer-based solid electrolytes with excellent comprehensive performances and construction of fast and stable ion transport channels at the electrolyte/electrode interfaces are of great significance for the successful development of solid-state lithium metal batteries. This paper presents a brief review of the research progress in solid polymer electrolytes from two aspects: Improving the ionic conductivities of solid polymer electrolytes and enhancing the interfacial performance at electrolyte/electrode interfaces. First, targeted optimization strategies on ionic conductivities of solid polymer electrolytes, including constructing continuously aligned ionic transport paths and shortening the ionic transport distance, are summarized. Second, interface optimization strategies, including constructing wetting interfaces and synthesizing asymmetric electrolytes, are presented to reduce the interface resistance and improve the interfacial contact. Finally, perspectives on the development of solid polymer electrolytes and high-performance solid-state lithium metal batteries are discussed, and key research directions and advanced test methods are proposed. This review may provide a comprehensive understanding and further guidance for not only the material design of solid polymer electrolytes, but also the structural design of lithium metal batteries with favorable electrochemical and interfacial performances.

Flexible and Safe Zinc/SS – Cu and Bi Incorporated Binder Free Hierarchical MnO2 Alkaline Solid-State Battery with High-Capacity Utilization and Long Cycle Life for Wearable Applications.

Wearable electronics are one of the most rapidly growing industries, due to their extended use in everyday applications resulting in an increased demand for portable energy storage devices. Despite immense success in commercialization of Lithium-ion batteries (LIBs), conventional LIBs suffer from issues of cost and safety. The expanding need for cheaper, and safer energy storage devices led explorations towards alternatives. After careful considerations, Zinc (Zn)-Manganese dioxide (MnO2) based alkaline system was chosen to be investigated in this work due to its low cost, inherent safety, and high theoretical energy density. However, challenges associated with making the aforementioned system rechargeable and highly performing still remains. The work in this study is directed towards enhancing the overall performance of the Zn-MnO2 alkaline battery in addition to making it suitable for flexible and wearable applications. A highly ionically conducting polymer electrolyte ({5}CP) with excellent physical and electrochemical stability primarily comprising biopolymer chitosan is prepared by using a time and energy-efficient technique. Incorporation of this polymer electrolyte with Zn anode and MnO2 cathode enabled the successful preparation of a physically flexible cell. To obtain high cyclability and performance of the system; issues of inactive phase formations (MnxOy, ZnMnxOy), low active material availability, pronounced shape changes at the anode surface, and zincate ion transfer towards cathode were overcome by enhancing the electrochemically active layers in the system. The assembled cell comprising the enhanced fabricated layers; (i.e. a Zinc/Stainless steel mesh composite anode, a hierarchical binder-free bismuth and copper additives based MnO2 cathode, and a chitosan-based polymer electrolyte with calcium hydroxide additive) indicated excellent rate capabilities (486 mAh/g @ 0.1 A/g, 278.9 mAh/g @ 2 A/g & 172.8 mAh/g @ 5 A/g), high capacity utilization (78% of the theoretical 2-electron capacity on MnO2), long cycling stabilities (70% retention over 1000 cycles), and good energy densities (155 – 400 Wh/kg @ 0.1 – 1 A/g). Moreover, a number of destructive tests such as being bent, hammered, pressurized, and punctured were conducted on the pouch cell fabricated using the above-mentioned layers to analyze the cells’ safety, reliability, and robustness. Results indicated not much deterioration in capacities. Additionally, when the cell was bent and tested for long performance; a stable discharge capacity (270 mAh/g @ 1 A/g) was obtained after 250 cycles, thus attesting to excellent cycling stability. The successful working of the fabricated cell was validated by lighting up an LED. The successful findings presented in this study can chart new pathways to the development of safe, flexible, cost-effective, and more environmentally responsible alternative energy storage sources for wearables.

Mn2O3 Incorporated Carbonized Bacterial Cellulose As Sulfur Host for Lithium-Sulfur Batteries

Early development and commercialization of lithium-ion batteries (LIBs) have enabled the portable electronic devices and powered the world. However, the ever-increasing demand for higher energy batteries have led to the quest for further improvement. Lithium-sulfur batteries (LSBs), with lithium anode and sulfur-based composite as cathode, have high theoretical specific energy of 2600 W h kg-1 (around 10 folds higher than LIBs system). Moreover, sulfur is produced as a by-product from petroleum refineries making research in LSBs more lucrative. However, there are a few critical challenges which restrict the commercialization of LSBs. First, insulating nature of sulfur (5 × 10-30 S cm-1) and lithium sulfide (Li2S, 10-13 S cm-1) impedes the electronic conductivity which results in low utilization of active sulfur. Secondly, the dissolution and diffusion of long-chain lithium polysulfides in electrolyte to lithium anode under concentration gradient causes series of severe issues such as loss of active sulfur, pulverization of lithium anode. Thirdly, the volume change during lithiation (up to 80%) results in degradation of cathode.To tackle aforementioned issues, we have utilized Mn2O3 incorporated carbonized bacterial cellulose (Mn2O3@CBC) as sulfur host for LSB. A facile melt-diffusion approach was adopted to encapsulate sulfur into Mn2O3@CBC matrix. The material was characterized using various physicochemical techniques - X-ray diffraction spectroscopy, Raman spectroscopy, Thermal gravimetric analysis, and Surface area analyzer. The Mn2O3@CBC system developed in this work offers the following benefits: (a) interconnected carbon nanofiber assembly which helps in fast diffusion of Li-ion and electrons; (b) porous morphology to accommodate volume change and to act as a reservoir for long-chain lithium polysulfides accumulation; (c) Mn2O3 as long-chain lithium polysulfide binding site and catalyst for conversion of long-chain lithium polysulfides to short-chain lithium polysulfides.To investigate the electrochemical property of the material, the performance is compared to bare sulfur and sulfur incorporated carbonized bacterial cellulose (S-CBC). Various electrochemical characterization such as cyclic voltammograms, galvanostatic charge-discharge, rate capability, long-term cycling was performed to investigate the performance of the materials. The material (S-Mn2O3@CBC) exhibited initial reversible capacity of 1150 mA h g-1 at 0.1C and retained 254.4 mA h g-1 at the extremely high current rate of 15C which is far ahead than the bare sulfur and S-CBC. Furthermore, the cycle life of LSB with low and high-sulfur loading was performed to further establish the advantage of using Mn2O3 as electro catalyst. Moreover, first-principles calculation was carried out to understand the functional mechanism for interaction of Mn2O3@CBC and intermediate lithium polysulfides. The excellent electrochemical performance substantiates that the S-Mn2O3@CBC is a good choice for cathode for LSBs. Figure 1

Multiscale modeling of dendrite formation in lithium-ion batteries

The commercialization of Lithium-ion batteries (LIBs) with Li metal anode has reached an impasse due to the unpredictable dendrite growth, which significantly deteriorates the battery performance. Previous studies show that dendrite growth is affected by the interplay among many factors, but the complex interaction between these factors has not been adequately addressed in the literature. In this work, we fill this knowledge gap by proposing a multiscale model for LIBs. Specifically, a kinetic Monte Carlo model describing dendrite formation at microscopic level is integrated with a macroscopic electrochemical model. Overall, the proposed model can (a) generate the evolution of macroscopic variables such as current density, Li-ion concentration, cell voltage, and state of charge, (b) explain their effects on the evolution of microscopic variables such as dendrite growth on the Li anode, and (c) provide a platform for optimal operation of LIBs to mitigate dendrite growth.

(Student Battery Slam Best Presentation Award Winner) Investigation of Tunable Properties in Single-Crystal LiNi0.5Mn1.5O4 Cathode Materials

The commercialization of lithium-ion batteries has played a pivotal role in the development of consumer electronics and electric vehicles. In recent years, much research has focused on the development and modification of the active materials of electrodes to obtain higher energies for a broader range of applications. High-voltage spinel materials including LiNi0.5Mn1.5O4 -δ (LNMO) have been considered as promising cathode materials to address the increasing demands for improved battery performance due to their high operating potential, high energy density, and stable cycling lifetimes.Spinel LNMO can adopt two crystallographic structures depending on the synthesis conditions: an ordered P4332 structure which contains Ni and Mn on separate octahedral sites and a disordered Fdm structure which contains Ni and Mn in a random arrangement on octahedral sites. The disordered spinel phase requires higher synthesis temperatures than the ordered phase to form and is often associated with the loss of oxygen from the material lattice, as well as the reduction of a small amount of electrochemically inactive Mn4+ to active Mn3+ for overall charge compensation. The differences in structure and Mn oxidation state of LNMO cathode materials can influence the electrochemical performance. Increased structural disorder can increase Li+ transport properties through reducing two-phase transformation domains, leading to improved rate performances. Through manipulation of synthetic parameters, the structural and electronic properties of LNMO can be well controlled during formation. The molten salt synthesis method has become one of the most prominent techniques to synthesize single-crystal layered and spinel materials.In this work, the molten salt synthesis method is used as a technique to tune both the morphology and Mn3+ content of high-voltage LNMO cathodes. The resulting materials are thoroughly characterized by a suite of analytical techniques, including synchrotron X-ray core-level spectroscopy, which are sensitive to the materials properties at multiple length scales. The multidimensional characterization allows us to build a materials library according to the molten salt phase diagram as well as to establish the relationship between synthesis, materials properties, and battery performance. Results of this work show that Mn3+ content is primarily dependent on the synthesis temperature and increases as temperature is increased. Particle morphology is mostly dependent on the composition of the molten salt flux, which can be tailored to obtain well-defined octahedrons enclosed by (111) facets, plates with predominant (11) facets, irregularly shaped particles, or mixtures of these. The electrochemical measurements indicate that the Mn3+ content has a larger contribution to the battery performance of LNMO than morphological characteristics and that a significant amount of Mn3+ could become detrimental to the battery performance. However, with similar Mn3+ contents, morphology still plays a role in influencing the battery cycle life and rate performance.We also employ high spatial resolution, synchrotron X-ray nanodiffraction techniques to identify the presence and quantify the percentage of the ordered versus disordered spinel phases at the individual particle level as LNMO single-crystal particles likely contain local regions of both ordered and disordered regimes which standard lab X-ray diffractometers may be unable to distinguish. The relationship between structural ordering and Mn3+ content is critical to the understanding of the intrinsic chemomechanical and electrochemical properties of LNMO. The insights of molten salt synthesis parameters on the formation and performance of LNMO, with deconvolution of the roles of Mn3+, crystal structure, and morphology, are crucial for continuing studies in the rational design of LNMO cathode materials for high energy Li batteries.

Improving the Energy Density of Ni-Rich Layered Cathodes: Through Increasing Nickel Composition or By Raising the Charge Cut-Off Voltage?

Since the commercialization of lithium-ion batteries, portable energy storage devices have undergone extensive development. This has allowed for the significant extension of their application areas especially large-scale applications such as plug-in hybrid electric vehicles and electric vehicles (EVs). However, the limited driving range, high costs, and safety concerns of electrified transportation systems are impeding their wider acceptance by society.1 Therefore, further improvements in the energy density, thermal stability, and cycle life of LIBs are necessary to accelerate their penetration into the automobile market.Generally, two approaches can be undertaken to enhance the energy density of NCM cathodes. The first approach is improving the specific capacity of the cathodes by increasing the composition of the redox-active nickel metal relative to other transition metals.2 This transition towards higher Ni produced positive effects in terms of energy density. However, it inevitably led to the deterioration of the cycling and thermal stability of the materials. The second approach is increasing the upper cut-off voltage to extract more Li+ ions. Enhancing the energy density of NCM-111 and NCM-523 has been investigated by operating at charge cut-off potentials higher than 4.3 V.3, 4 However, there is no report directly comparing electrochemical, structural, and thermal properties of the cathodes which are currently used (NCM-622) and will be adapted (NCM-811 and NCM-90) for EVs.In this study, the two approaches, increasing the Ni contents and the upper cut-off potential for high energy density, are directly compared. The comparative study is specifically carried out in terms of capacity and cycling lifespan as well as thermal stability. References S.-T. Myung, F. Maglia, K.-J. Park, C. S. Yoon, P. Lamp, S.-J. Kim and Y.-K Sun., ACS Energy Lett., 2017, 2, 196.H.-J. Noh, S. Youn, C. S. Yoon and Y.-K. Sun, J. Power Sources, 2013, 233, 121.J. Kasnatscheew, M. Evertz, B. Streipert, R. Wagner, S. Nowak, I. C. Laskovic and M. Winter, J. Phys. Chem. C, 2017, 121, 1521.J. A. Gilbert, J. Bareno, T. Spila, S. E. Trask, D. J. Miller, B. Z. Polzin, A. N. Jansen and D. P. Abraham, J. Electrochem. Soc., 2017, 164, A6054.

Designing High Performance Organic Batteries.

ConspectusRedox active organic and polymeric materials have witnessed the rapid development and commercialization of lithium-ion batteries (LIBs) over the last century and the increasing interest in developing various alternatives to LIBs in the past 30 years. As a kind of potential alternative, organic and polymeric materials have the advantages of flexibility, tunable performance through molecular design, potentially high specific capacity, vast natural resources, and recyclability. However, until now, only a handful inorganic materials have been adopted as electrodes in commercialized LIBs. Although the development of carbonyl-based materials revived organic batteries and stimulated plentiful organic materials for batteries in the past 10 years due to their high theoretical capacities and long-term cycleabilities compared with their pioneers (e.g., conducting polymers), organic batteries are still facing many challenges. For example, it is still essential to enhance the theoretical and experimental capacities of organic materials. Moreover, typically, organic materials suffer relatively low conductivity, which limits their rate capability. In addition, many organic materials, especially small molecules, show poor cycling stability because of their dissolution in organic electrolytes. Other requirements, such as high voltage output and low cost, are also crucial for organic batteries. Therefore, insights into fundamentals (e.g., intramolecular and intermolecular interactions) for a deep understanding of organic batteries and constructive strategies ranging from material design to manipulation of other components (e.g., conductive additives, binders, electrolytes, and separators through controlling the intramolecular and intermolecular interactions and manipulating the ionic transport) are of great significance to boost the performance of organic batteries.In this Account, we give an overview of our efforts to develop high performance organic batteries with various strategies from the aspects of molecular design and the manipulation of other components. Inspired by the experience in organic electronics, we proposed that the extension of the π-conjugated system is helpful for stabilizing the +1/-1 charge/discharge states, improving the charge transport, and facilitating the layered packing (good for ionic diffusion) and hence would benefit the rate capability and cyclability. The π-d conjugation can effectively improve the electrical conductivity and provide stable and fast ionic storage, which enriches the materials for high-performance batteries and further deepens the understanding of conjugated coordination polymers (CCPs). Different from inorganic materials, organic materials are composed of molecules (either small molecules, macromolecules, or polymeric molecules) with weak intermolecular interactions. Therefore, the manipulation of active molecules or additives (conductive additives, binders, and other special additives) through control of intermolecular interactions is crucial for enhancing the electrochemical performance of organic batteries. Regarding the possible dissolution of active materials, the modification of separators through addition of selectively permeable membranes as ionic sieves is the most efficient and universal strategy to mitigate the shuttling of dissolved molecules but allow smaller sized cations to pass and hence is able to enhance the cyclability. On the basis of these findings, the challenges and several future trends for organic batteries are discussed. This Account provides a summary of our recent progress, understanding of the fundamentals for high performance organic batteries, insight into the intramolecular and intermolecular interactions, and prospects for future development of organic materials for next-generation rechargeable batteries.

Further Understanding and Modeling of the Thermal Runaway of High Energy Density Lithium-Ion Batteries

Since the commercialization of Lithium-Ion Battery (LIB) by Sony Inc. in 1991 until today, recurrent incidents involving LIBs have been reported worldwide. During these incidents, the most energetic catastrophic failure of a LIB system is a cascading thermal runaway event. It is characterized by a deficit of energy dissipation versus energy accumulation in the cells leading to uncontrollable overheating of the battery system [1,2]. This complex event involves multi-scale phenomena ranging from internal parallel or cascading physico-chemical to battery components reactions (electrodes, electrolytes & separator) and further to the thermal propagation of cell core & safety features. Complexity of the comprehensive understanding of the thermal runaway hazard also lies in the fact that both normal operation (through aging and relating medium/long term degradation effects) and abuse conditions can contribute to a thermal runaway event, as recently discussed by [2] or [3].Battery safety is becoming even more critical with the emergence of highly reactive Ni-rich LIBs in the market. These batteries are commercialized to meet novel energy- or power-demanding applications and are expected to dominate the market in the coming years, likely until the occurrence of a new technological breakthrough. Therefore, these newly introduced LIBs presenting such high energy density characteristics and integrating more intrinsically reactive materials could possibly lead to more catastrophic events subsequent to the thermal runaway. Therefore, there is a clear need to better understand the underlying specific electrochemical and thermal behaviors of these technologies in both normal and abuse conditions across their lifetime. Inspired by the former collaborative IFPEN/INERIS research works on the thermal runaway of LIBs (essentially focused on LFP/Graphite and relating batteries) [2], this work aims to go deeper into the understanding & modeling of this complex phenomenon at cell scale, taking into account the influence of novel highly reactive technologies and the influence of aging with 2 target degradation mechanisms: SEI growth and Li Plating, in order to understand what the keys are towards inherently safer design and operation of highly reactive LIBs. It is a matter of establishing the link between the materials used (electrodes, electrolytes) in high energy density & intrinsically reactive LIB technologies, the degradation products during cell calendar and cycling aging (mainly analyzed through SEI evolution during cell lifetime and Li deposition during cold recharges) as well as the thermal runaway kinetics.The selected technologies studied in this research are two commercial 18650 Ni-rich LIBs, namely a Panasonic NCR GA and a LG HG2, which were based on Li(Ni0.8Co0.15Al0.05)O2 (NCA) and Li(Ni0.8Mn0.1Co0.1)O2 (NMC811), respectively, for positive electrodes, in combination with graphite-SiOx composite negative electrodes.With the goal of finding the keys factors that can improve the safety of these highly reactive LIBs during usage, the research strategy relies on the achievements of the previous projects and on the synergism offered by combined experimental and modeling studies as illustrated in Figure 1.The experimental study includes the 3 interconnected experimental processes here after specified: a complete multi-scale cell analysis in order to analyze the pristine, aged and thermally abused cells;a safety-focused aging campaign in order to artificially age battery samples, focusing on each target mechanism (SEI growth, Lithium plating) in a controlled and measurable way;accelerating rate calorimetry (ARC)thermal abuse tests in quasi-adiabatic conditions at cell level in order to qualifying the thermal runaway phenomenon as well as calibrating the thermal runaway model. The modeling study leads to the development of an extended thermal runaway model in order to predict the behaviors of different LIBs nearby and during thermal runaway under field conditions. This coupled multi-physics model will improve and extend the initial thermal runaway model built by [2] by integrating the impact of Li plating & SEI-driven cycling aging.The final result will be a multi-dimensional multiphysical model of LIB capable of accounting for the triggering of runaway under different thermal and electrical conditions and as a function of the state of aging. The predictions of the models will be validated based on other thermal abuse tests. This model will further be implemented to understand the electrical or thermal initiation of the phenomenon of thermal runaway and its propagation within a battery pack regarding its design. They will eventually be transposed into tools enabling the best design of the packs and avoidance of this undesirable phenomenon.

Achieving high-energy dual carbon Li-ion capacitors with unique low- and high-temperature performance from spent Li-ion batteries

Graphite is the dominant choice as negative electrode since the commercialization of lithium-ion batteries, which could bring about a significant increase in demand for the material owing to its usage in forthcoming graphite-based energy storage devices.

Progress in Thermal Modeling for Lithium-ion Battery

Safety issue is the main obstacle for the commercia-lization of lithium ion batteries, which include smoke, fire and even explosion caused by thermal runaway or other extreme conditions. In order to reduce the hazards of safety issue, numerous modeling work have been proposed for lithium ion batteries to analyze the thermal behavior and thermal runaway mechanism over the past years. Herein, this review is concerned with the development of thermal modeling on lithium ion batteries. The thermal models have been developed to study the temperature distribution of battery and the relationship between thermal behavior and the reactions inside battery under different working conditions. They could accurately predict batteries’ performance and thermal runaway occurrence by analyzing modeling data, providing reliable information for the design and management of batteries. Finally, some perspectives of safety for lithium ion battery are proposed for further development.

Nitrogen-rich hierarchically porous carbon as a high-rate anode material with ultra-stable cyclability and high capacity for capacitive sodium-ion batteries

Carbon-based anode materials hold a promising future for sodium-ion batteries (SIBs) due to their natural abundance and low cost of development. In spite of carbon's important role in the commercialization of lithium-ion batteries (LIBs), further exploration is necessary in order to find high-performance, high-rate carbon anode materials for SIBs. A honeycomb-like, nitrogen-rich (17.72 at%), hierarchically porous, and highly disordered carbonaceous material (N-HC) with an expanded interlayer distance (0.44 nm in average) is synthesized by spray drying and subsequent pyrolysis under flowing NH3. The hierarchically porous structure and rich nitrogen doping result in a large specific surface area (722 m2 g−1), more defects and active sites, and greater functional interface accessibility for the active porous carbonaceous material and electrolyte. When N-HC is used as the anode material for SIBs, the batteries display favorable discharge capacities (255.9 mA h g−1 in the 3000th cycle at 500 mA g−1) and good capacitive-energy-storage behavior (67% at a scan rate of 0.5 mV s−1) with excellent high-rate performance and ultra-stable cyclability over 10,000 cycles at 5000 mA g−1. Our results show that the combination of the hierarchically porous structure and nitrogen doping leads to improved energy storage by increasing the capacitive energy storage, which enhances the high-rate performance of N-HC. To further enhance the performance of the material, an electrical pretreatment is employed to increase the initial Coulombic efficiency of N-HC to 79.5%, a record high for an SIB cell. A full cell with an N-HC anode and a Na3V2(PO4)3/C cathode shows a high capacity with a favorable cyclability (238.7 mA h g−1 after 100 cycles at 100 mA g−1 and a capacity retention of 95.3% compared to the second cycle).

Electrochemical performance and interfacial investigation on Si composite anode for lithium ion batteries in full cell

Abstract Lithium ion batteries (LIBs) containing silicon (Si) as a negative electrode have gained much attention recently because they deliver high energy density. However, the commercialization of LIBs with Si anode is limited due to the unstable electrochemical performance associated with expansion and contraction during electrochemical cycling. This study investigates the electrochemical performance and degradation mechanism of a full cell containing Si composite anode and LiFePO4 (lithium iron phosphate (LFP)) cathode. Enhanced electrochemical cycling performance is observed when the full cell is cycled with fluoroethylene carbonate (FEC) additive compared to the standard electrolyte. To understand the improvement in the electrochemical performance, x-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) are used. Based on the electrochemical behavior, FEC improves the reversibility of lithium ion diffusion into the solid electrolyte interphase (SEI) on the Si composite anode. Moreover, XPS analysis demonstrates that the SEI composition generated from the addition of FEC consists of a large amount of LiF and less carbonate species, which leads to better capacity retention over 40 cycles. The effective SEI successively yields more stable capacity retention and enhances the reversibility of lithium ion diffusion through the interphase of the Si anode, even at higher discharge rate. This study contributes to a basic comprehension of electrochemical performance and SEI formation of LIB full cells with a high loading Si composite anode.

Bimetallic metal-organic framework derived Co3O4-CoFe2O4 composites with different Fe/Co molar ratios as anode materials for lithium ion batteries.

Developing high-performance electrode materials to replace a traditional graphite electrode is critical for the commercialization of lithium ion batteries, which however still remains a great challenge. Herein, we report a suitable method to synthesize a series of well-dispersed nanostructured Co3O4-CoFe2O4 composites (CCFs) from bimetallic metal-organic frameworks (BiMOFs) with varied Fe3+/Co2+ molar ratios. When used as anodes for lithium ion batteries, the CCF-12 composite exhibits a maximum initial discharge capacity of 1328 mA h g-1, a reversible capacity of 940 mA h g-1 at 100 mA g-1 after 80 cycles, and a better rate capability in comparison with those of pure Co3O4 and other CCF composites. The well-dispersed structure and small particle size are believed to mainly contribute to the outstanding electrochemical performance of CCF-12 electrodes.

Approaching High-Performance Li-Sulfur Batteries By Surface Modification Using Atomic Layer Deposition

Approaching High-Performance Li-Sulfur Batteries by Surface Modification Using Atomic Layer Deposition Xiangbo Meng†#, Yuzi Liu‡, Joseph A. Libera†, Kevin R. Zavadil§ and Jeffrey W. Elam†* † Energy Systems Division, ‡ Center for Nanoscale Materials, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL, USA 60439 § Materials Science and Engineering, Sandia National Laboratories, Albuquerque, NM, USA 87185 # Presenting author: xmeng@anl.gov; * Corresponding author: jelam@anl.govElectrical energy storage (EES) is critical for the widescale implementation of renewable clean energies. With the commercialization of lithium-ion batteries (LIBs) in portable electronics, new battery technologies are being intensively investigated in order to provide higher energy density for other applications such as electrical vehicles. Lithium-sulfur (Li-S) batteries are very intriguing, given their high theoretical specific energy density of 2567 Wh/kg. However, Li-S batteries suffer from a number of major hurdles in practice, such as the insulating S and Li2S, soluble polysufides (Li2Sx, x≥4), and lithium dendrite growth. Although a huge amount of research effort has been invested to date, a lack of viable technologies exists to create high performance for practical applications. In our recent studies, both S cathodes and lithium metal anodes were modified via atomic layer deposition (ALD). Our research disclosed that uniform and conformal ALD coatings are very beneficial for Li-S batteries to approach high performance. Specifically, effects of ALD coating were exhibited in: (1) depressing the shuttle effect of polysulfides and (2) inhibiting lithium dendrite growth. As a result, the ALD-modified Li-S batteries showed improved Coulombic efficiency, much longer cycling lifetime, and enhanced safety. In our studies, different ALD coatings were investigated, including Al2O3 and LixAlyS. This work was supported as part of the Joint Center for Energy Storage Research (JCESR), an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (BES). Electron microscopy was performed at Center for Nanoscale Materials at Argonne National Laboratory.

Rapid Mapping of Lithiation Dynamics in Transition Metal Oxide Particles with Operando X-ray Absorption Spectroscopy

Since the commercialization of lithium ion batteries (LIBs), layered transition metal oxides (LiMO2, where M = Co, Mn, Ni, or mixtures thereof) have been materials of choice for LIB cathodes. During cycling, the transition metals change their oxidation states, an effect that can be tracked by detecting energy shifts in the X-ray absorption near edge structure (XANES) spectrum. X-ray absorption spectroscopy (XAS) can therefore be used to visualize and quantify lithiation kinetics in transition metal oxide cathodes; however, in-situ measurements are often constrained by temporal resolution and X-ray dose, necessitating compromises in the electrochemistry cycling conditions used or the materials examined. We report a combined approach to reduce measurement time and X-ray exposure for operando XAS studies of lithium ion batteries. A highly discretized energy resolution coupled with advanced post-processing enables rapid yet reliable identification of the oxidation state. A full-field microscopy setup provides sub-particle resolution over a large area of battery electrode, enabling the oxidation state within many transition metal oxide particles to be tracked simultaneously. Here, we apply this approach to gain insights into the lithiation kinetics of a commercial, mixed-metal oxide cathode material, nickel cobalt aluminium oxide (NCA), during (dis)charge and its degradation during overcharge.

Physical and Electrochemical Characterization of Li2FeP2O7/C Nanocomposites Prepared By a Combination of Spray Pyrolysis and Wet Ball Milling Followed By Heat Treatment

Introduction Since the commercialization of lithium-ion batteries in the 1990s, they have been widely utilized for energy storage in mobile electric devices owing to their large gravimetric and volumetric energy densities. Recently, attention has turned to the use of them as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs). Large-scale batteries require safety, low-cost, long cycle-life, and high energy and power densities. Furthermore, it is well known that the cathode materials have a significant impact on battery capacity, cycle life, safety and cost. Recently, pyrophosphates (Li2MP2O7, M=transition metal), the polyanion compounds with 3D crystal structure, have come into sight as a new candidate of cathode materials [1, 2]. Thus far, we have investigated the synthesis of LiMPO4/C (M=Fe, Mn and Co) nanocomposites by a combination of aerosol and powder technologies followed by heat treatment, and then reported that the composite electrodes showed a good electrochemical performance [3-5]. In this work, the synthesis of Li2FeP2O7/C nanocomposites has been prepared by a combination of spray pyrolysis (SP) and wet ball milling (WBM) followed by heat treatment and their physical and electrochemical properties have been also studied. Experimental The precursor solution used in this study was prepared by dissolving stoichiometric amounts of LiNO3,H3PO4 and Fe(NO3)3¥9H2O in distilled water and then atomized at a frequency of 1.7MHz using an ultrasonic nebulizer. Ascoribic acid was added into the precursor solution as a reducing agent. The sprayed droplet were transported to a reactor using a 3% H2+N2 gas with a gas flow rate of 4 L min-1 , heated at 800 oC and converted into solid particles. The resulting particles were then milled with acetylene black (AB) in ethanol by high-energy planetary ball milling, and then annealed at 600 oC for 2 h in a 3% H2+N2 atmosphere to obtain the desired material. The crystalline phase of the samples was studied by X-ray diffraction (XRD) analysis using Cu-Kα radiation. The surface morphology of the samples was examined by scanning electron microscopy (SEM) at 8 kV. The electrochemical performance of Li2FeP2O7/C nanocomposite was investigated using coin-type cells (CR2032). A 1 mol dm-3 LiPF6 solution in a solvent mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) in 1:1 volume ratio (Tomiyama Pure Chemical Co., Ltd.) was used as the electrolyte. The cathode consisted of 70 wt. % Li2FeP2O7/C, 10 wt. % polyvinylidene fluoride (PVdF) as a binder and 20 wt. % acetylene black. The cells were cycled in a constant current-constant voltage mode at a 0.05 C rate (1 C = 110 mA g−1) to 4.3 V, held at 4.3 V until C/100, and then discharged to 2.0 V at a 0.05C rate. Results and discussion Fig. 1 shows the XRD patterns of the samples prepared by spray pyrolysis (SP) at 800 oC (a) and then annealed at 600 oC for 2 h in a 3%N2+H2 gas atmosphere (b). The XRD pattern of the sample prepared by SP with annealing was indexed to the pure-phase of Li2FeP2O7. Fig. 2a shows the SEM image of Li2FeP2O7 prepared by SP and then annealed at 600 oC. The final sample consists of spherical particles with approximately several micrometers in size. The charge-discharge curves of the Li2FeP2O7/Li cell were shown in Fig. 2b. The discharge capacity at 1st cycle was 64 mAh g-1, which corresponds to 58% of its theoretical capacity (110 mAh g-1). This fact may be due to its low electronic and iron conductivities.The synthesis of Li2FeP2O7/C nanocomposite was carried out using a combination of SP at 800 oC and WBM with heat treatment annealed at 600 oC. Fig. 3 shows the charge-discharge curves of the Li2FeP2O7/C nanocomposite /Li cell. The cell exhibited an initial discharge capacity of 100 mAh g-1, which corresponds to 91% of its theoretical capacity. Also, it shows a discharge capacity of 96 mAh g-1 at 5th cycle. The Li2FeP2O7/C composite cathode exhibited a wide and flat potential plateau at approximately 3.5 V vs Li. These facts may indicate that the WBM process is an effective way to improve the electrochemical properties of Li2FeP2O7 electrode. References L. Adam, A. Guesdon, and B. Raveau, J. Solid State Chem., 181, 3110( 2008). P. Barpanda, T. Ye, S.-C. Chung, Y. Yamada, S. Nishimura, and A. Yamada, J. Mater. Chem., 22, 13455(2012). M. Konarova and I. Taniguchi, J. Power Sources, 195, 3661-3667(2010). Z.Bakenov and I. Taniguchi, Electrochem. Commun., 12, 75-78(2010) T. N. L. Doan and I. Taniguchi, J. Power Sources, 195,5679-5684(2011). Figure 1