Nickel Manganese Cobalt Oxide Cathode Research Articles

Effective Thermal Conductivity of Lithium‐Ion Battery Electrodes in Dependence on the Degree of Calendering

The thermal conductivity represents a key parameter for the consideration of temperature control and thermal inhomogeneities in batteries. A high‐effective thermal conductivity will entail lower temperature gradients and thus a more homogeneous temperature distribution, which is considered beneficial for a longer lifetime of battery cells. Herein, the impact of the microstructure within the porous electrode coating obtained by different compression rates and its thermal contact to the current collector is investigated as both factors significantly determine the overall conduction through the electrode. The effective thermal conductivity of two graphite anodes and two lithium nickel manganese cobalt oxide cathodes is evaluated at different compression rates. It is found that the thermal conductivity does not have a monotone dependence on the porosity with changing compression rates. The results show a strong correlation with the adhesion strength, thus a significant impact of the thermal contact resistance between the coating and current collector is assumed.

The Effect of Doping Process Route on LiNiO2 Cathode Material Properties

The pursuit of higher energy density in lithium-ion batteries has driven the increase of the nickel content in lithium nickel cobalt manganese oxide cathode active materials (CAMs), ultimately approaching LiNiO2 (LNO). The downside of the high specific capacity of LNO is more severe degradation of the CAM during battery operation. A common approach to increase structural stability is the introduction of dopants. Various dopants are discussed and compared with each other when integrated into the CAM and tested against undoped materials in the literature, but little attention is given to the role of the process route of their introduction. In this work, we demonstrate with a series of nominally equally Zr-doped LNO samples that effects on various physico- and electrochemical properties are due not to the dopant itself, as one would assume in comparison to an undoped sample, but to the process route and the resulting particle morphology. Dopant, concentration and process routes (co-precipitation, impregnation and co-calcination) were chosen based on their significance for industrial application.

A social life cycle assessment of vanadium redox flow and lithium‐ion batteries for energy storage

AbstractBattery energy storage systems (BESS) are expected to fulfill a crucial role in the renewable energy systems of the future. Within current regulatory frameworks, assessing the sustainability as well as the social risks for BESS should be considered. In this research we conducted a social life cycle assessment (S‐LCA) of two BESS: the vanadium redox flow battery (VRFB) and the lithium‐ion battery (LIB). The S‐LCA was conducted based on the guidelines set by UNEP/SETAC and using the PSILCA v.3 database. It was found that most social risks related to the life cycle of the batteries are associated with the raw material extraction stage, while sectors related to chemicals also entail considerable risks. Workers are the stakeholder group affected most. These results apply to supply chains located in both China and Germany, but risks were lower for similar supply chains in Germany. An LIB with a nickel manganese cobalt oxide cathode is associated with considerably larger risks compared to a LIB with lithium manganese oxide cathode. For a VRFB life cycle with an increased vanadium price, the social risks were higher than those of the VRFB supply chain with a regular vanadium price. Our paper shows that S‐LCA through the PSILCA database can provide interesting insights into the potential social risks associated with a certain product's life cycle. Generalizations of the results are not recommended, and one should be careful with assessments for technologies that have not yet matured due to the cost sensitivity of the methodology.

Characterization and Thermal Treatment of the Black Mass from Spent Lithium-Ion Batteries

Recycling lithium-ion batteries is crucial for the environment and the sustainability of primary resources. In this paper, we report on the characterization of two grades of black mass from spent lithium-ion batteries (with typical lithium–nickel–manganese–cobalt oxide cathode compositions) and their behavior during heating trials. This study paves the way for optimizing lithium-ion battery recycling processes by fully characterizing black mass samples before and after heating. A gas release under pyrolytic conditions was detected using a multicomponent mass spectrometer and included dimethyl carbonate, diethyl carbonate, oxygenated hydrocarbons, hydrocarbons, and other miscellaneous gases. This can be attributed to the evaporation of volatile organic compounds, conductive salt, organic polyvinylidene fluoride binder, and an organic separator such as polypropylene. Thermal treatment led to the partial decomposition of the binder into char and newly formed fluorine cuboids. The compaction of the cathode decreased, but the remaining binder limited recycling processes. By heating the black mass samples to 900 °C, the intensity of the X-ray diffraction graphitic carbon peak decreased, and the lithium metal oxides were reduced to their corresponding metals. The graphite in the black mass samples was structurally more disordered than natural graphite but became more ordered when heated.

Front Cover: Synergistic Effects of Surface Coating and Bulk Doping in Ni‐Rich Lithium Nickel Cobalt Manganese Oxide Cathode Materials for High‐Energy Lithium Ion Batteries (ChemSusChem 4/2022)

The Front Cover shows multiple treatment choices for the modification of cathode active materials for lithium-ion batteries. Like for a car wash program, the treatment will typically result in an improvement of the status quo. However, the best treatment procedure will only become clear if all options are explored. In the present work, this means to not only investigate various coated samples, but also samples modified via the same heat-treatment without coating. More information can be found in the Research Article by Friederike Reissig et al.

Synergistic Effects of Surface Coating and Bulk Doping in Ni-Rich Lithium Nickel Cobalt Manganese Oxide Cathode Materials for High-Energy Lithium-Ion Batteries.

Invited for this month's cover is a combined work of the Helmholtz Institute Münster together with the MEET Battery Research Center and the Universities of Münster and Mainz. The cover shows multiple treatment choices for the modification of cathode active materials for lithium-ion batteries. Similar to a car wash program, the treatment will typically result in an improvement of the status quo. However, the best treatment procedure will only become clear if all modification pathways are explored. The Research Article itself is available at 10.1002/cssc.202102220.

Synergistic Effects of Surface Coating and Bulk Doping in Ni-Rich Lithium Nickel Cobalt Manganese Oxide Cathode Materials for High-Energy Lithium Ion Batteries.

Ni‐rich layered oxide cathodes are promising candidates to satisfy the increasing energy demand of lithium‐ion batteries for automotive applications. Thermal and cycling stability issues originating from increasing Ni contents are addressed by mitigation strategies such as elemental bulk substitution (“doping”) and surface coating. Although both approaches separately benefit the cycling stability, there are only few reports investigating the combination of two of such approaches. Herein, the combination of Zr as common dopant in commercial materials with effective Li2WO4 and WO3 coatings was investigated with special focus on the impact of different material processing conditions on structural parameters and electrochemical performance in nickel‐cobalt‐manganese (NCM) || graphite cells. Results indicated that the Zr4+ dopant diffusing to the surface during annealing improved the electrochemical performance compared to samples without additional coatings. This work emphasizes the importance to not only investigate the effect of individual dopants or coatings but also the influences between both.

Self-heating ignition of large ensembles of Lithium-ion batteries during storage with different states of charge and cathodes

Self-heating is a possible cause of ignition of the open-circuit Lithium-ion battery (LIB) during storage. However, previous studies mainly focused on self-heating of a single cell, without considering the effect of heat transfer on large-size storage. In this study, a one-dimensional computational model, coded in the Gpyro, is used to study ensembles containing 1 cell to 5 million cells. Results show that ignition occurs at the central cell of the ensemble, while the outer surfaces remain at ambient temperature. As the length of ensembles increases from 0.01 m to 10 m, cell thermal runaway temperatures quantified using the critical temperature increase rate of 10 °C/min as defined in standard SAE-J2464 are insensitive to ensemble size, decreasing from 188 °C to 184 °C, but the critical ambient temperature triggering ignition decreases with size from 183 °C to 98 °C. This shows that the critical ambient temperature should be used to guide storage rather than the standard suggested critical temperature increase rate, which does not represent the criticality of ignition. The model predicts that higher state of charge (SOC) cells are easier to self-ignite. An ensemble containing 5 million 80% SOC cells can self-ignite at 40 °C. Self-heating ignition propensity of the Lithium Cobalt Oxide cathode LIB is larger, compared with Lithium Nickel Cobalt Manganese Oxide cathode. This study finds that the SAE-J2464 standard is not sufficiently robust to understand self-heating ignition during storage, and predicts the effect of the SOC and cathode chemistry on critical ambient temperature, contributing to the protection against LIB fires.

Enhancing the stabilities and electrochemical performances of LiNi0.5Co0.2Mn0.3O2 cathode material by simultaneous LiAlO2 coating and Al doping

Superior environmental and thermal stabilities and well-defined electrochemical performances of lithium nickel cobalt manganese oxide cathode materials are needed for next-generation high-performance and safe lithium-ion batteries, to which appropriate modification means have been proven to be crucial for enhancing the properties for these materials. Herein, we develop a facile in-situ approach to co-modify LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode material with simultaneous lithium aluminum oxide (LiAlO2) coating and Al doping. Without any additional steps and reagents, the co-modification begins during the preparation of the hydroxide precursor of NCM523 and ends upon the calcination of the cathode material. Combining the synergistic effects from LiAlO2 coating and Al doping, the resultant Al-modified NCM523 possesses a robust protective layer as well as a well-ordered layered structure with enlarged lattice spacing, restrained cation mixing, and concentration-gradient-distributed Ni, thus exhibiting significantly enhanced environmental and thermal stabilities and electrochemical performances over its pristine counterpart. At a high active material content of 94.0 wt.% and a high mass loading of 19.5 mg cm−2 for the testing electrode, the optimized Al-modified NCM523 shows a high discharge capacity (168.4 mAh g−1 at 0.1 C), a high rate capability (capacity retains 67.8% at 3.0 C vs. 0.1 C), and a long cycle life (capacity retains 62.3% after charge / discharge at 0.5 C for 120 cycles). Reasonably, the unique in-situ co-modification approach developed in the present work can be applied for other NCMs with simultaneous LiAlO2 coating and Al doping. More broadly, apart from Al, this approach may be further extended to utilize other modification chemistries to co-modify NCMs and other cathode materials in situ for enhancing their stabilities and electrochemical performances.

Layered Heterostructure Ionogel Electrolytes for High-Performance Solid-State Lithium-Ion Batteries.

Ionogel electrolytes based on ionic liquids and gelling matrices offer several advantages for solid-state lithium-ion batteries, including nonflammability, wide processing compatibility, and favorable electrochemical and thermal properties. However, the absence of ionic liquids that are concurrently stable at low and high potentials constrains the electrochemical windows of ionogel electrolytes and thus their high-energy-density applications. Here, ionogel electrolytes with a layered heterostructure are introduced, combining high-potential (anodic stability: >5V vs Li/Li+ ) and low-potential (cathodic stability: <0V vs Li/Li+ ) imidazolium ionic liquids in a hexagonal boron nitride nanoplatelet matrix. These layered heterostructure ionogel electrolytes lead to extended electrochemical windows, while preserving high ionic conductivity (>1mScm-1 at room temperature). Using the layered heterostructure ionogel electrolytes, full-cell solid-state lithium-ion batteries with a nickel manganese cobalt oxide cathode and a graphite anode are demonstrated, exhibiting voltages that are unachievable with either the high-potential or low-potential ionic liquid alone. Compared to ionogel electrolytes based on mixed ionic liquids, the layered heterostructure ionogel electrolytes enable higher stability operation of full-cell lithium-ion batteries, resulting in significantly enhanced cycling performance.

Coupled electro-thermal modeling of lithium-ion batteries for electric vehicle application

The lithium-ion battery is a complex system that is both non-linear and non-stationary, which involves electrical, thermal and electrochemical dynamics In order to deepen the understanding of battery system dynamics, in this paper, an electro-thermal coupled model is proposed for a 40 Ah lithium-ion battery cell with Nickel Manganese Cobalt Oxide cathode material and graphitic anode. The developed model takes into account the dynamics of the high power applications and then allows to accurately present the physicochemical phenomena occurring in a battery cell. It is built through a dynamic equivalent circuit and a thermal model. The battery is divided into n×m nodes with two dimensions and each node is represented by an equivalent circuit. Both models are coupled in the same loop, the electric-thermal through the distribution of power losses to calculate the distribution of temperature and the thermal-electric through the mean temperature of the battery to update the electric parameters. The obtained results show that the proposed model is able to simulate the dynamic interaction between the electric and the thermal battery behavior, and high performance for the cell surface temperature prediction.

R-F Sputtered Ultrathin Organic/Inorganic Bilayer for Dendrite Free Li Deposition

Lithium metal anodes have attracted great attention due to its high theoretical capacity and low redox potential. However, the notorious reactivity, uncontrolled solid electrolyte interphase (SEI) and undesired results in low battery performance and risk for safety concern. To resolve these problems, radio frequency (R-F) sputtered ultrathin bilayer of graphite and SiO2 ultrathin bilayer on a Li metal was demonstrated, for the first time, as an effective SEI layer. The graphite-SiO2 bilayer modified Li anode showed an improved capacity retention of 98.57% for lithium nickel cobalt manganese oxide cathode (NMC111) and 96.78% for lithium titanate (LTO), compared to bare Li anodes at 82.73% (NMC111) and 92.31% (LTO), respectively. Higher capacity, longer cycling stability and lower voltage hysteresis were obtained with the use of the graphite and SiO2 modified Li anode. Graphite acts as an electrical bridge between the plated Li and Li electrode, which lowers the impedance and buffers the volume expansion during Li plating/stripping. The addition of an ultrathin SiO2 layer facilitates Li diffusion and lithiation/delithiation, provides higher electrolyte affinity, higher chemical stability, and higher Young’s modulus to suppress the Li dendrite growth. This novel technique can open further pathways towards practical realization of use of lithium metal battery (LMB) in high energy density battery technologies such as Li-S and Li-air battery.

Interconnected Two‐dimensional Arrays of Niobium Nitride Nanocrystals as Stable Lithium Host

AbstractThe cycle life of rechargeable lithium (Li)‐metal batteries is mainly restrained by dendrites growth on the Li‐metal anode and fast depletion of the electrolyte. Here, we report on a stable Li‐metal anode enabled by interconnected two‐dimensional (2D) arrays of niobium nitride (NbN) nanocrystals as the Li host, which exhibits a high Coulombic efficiency (&gt;99 %) after 500 cycles. Combining theoretical and experimental analysis, it is inferred that this performance is due to the intrinsic properties of interconnected 2D arrays of NbN nanocrystals, such as thermodynamic stability against Li‐metal, high Li affinity, fast Li+ migration, and Li+ transport through the porous 2D nanosheets. Coupled with a lithium nickel–manganese–cobalt oxide cathode, full Li‐metal batteries were built, which showed high cycling stability under practical conditions – high areal cathode loading ≥4 mAh cm−2, low negative/positive (N/P) capacity ratio of 3, and lean electrolyte weight to cathode capacity ratio of 3 g Ah−1. Our results indicate that transition metal nitrides with a rationally designed structure may alleviate the challenges of developing dendrite‐free Li‐metal anodes.

Synthesis and Manipulation of Single-Crystalline Lithium Nickel Manganese Cobalt Oxide Cathodes: A Review of Growth Mechanism.

Lithium nickel manganese cobalt oxide (NMC) cathodes are of great importance for the development of lithium ion batteries with high energy density. Currently, most commercially available NMC products are polycrystalline secondary particles, which are aggregated by anisotropic primary particles. Although the polycrystalline NMC particles have demonstrated large gravimetric capacity and good rate capabilities, the volumetric energy density, cycling stability as well as production adaptability are not satisfactory. Well-dispersed single-crystalline NMC is therefore proposed to be an alternative solution for further development of high-energy-density batteries. Various techniques have been explored to synthesize the single-crystalline NMC product, but the fundamental mechanisms behind these techniques are still fragmented and incoherent. In this manuscript, we start a journey from the fundamental crystal growth theory, compare the crystal growth of NMC among different techniques, and disclose the key factors governing the growth of single-crystalline NMC. We expect that the more generalized growth mechanism drawn from invaluable previous works could enhance the rational design and the synthesis of cathode materials with superior energy density.

New Thiourea-Based Ionic Liquid as an Electrolyte Additive to Improve Cell Safety and Enhance Electrochemical Performance in Lithium-Ion Batteries.

Our society is critically dependent on lithium-ion batteries (LIBs) as a power source for portable electronic gadgets. One of the major problems with these batteries is the degradation of the materials inside them. In addition to the reduced cell life, building-up of these degraded products inside the cells is very detrimental to the safe operation. Herein, we report the synthesis and characterization of a novel thiourea-based room temperature ionic liquid (IL), 3-heptyl-1-(3-(3-heptyl-3-phenylthioureido)propyl)-1H-imidazole-3-ium hexafluorophosphate. Its electrochemical and thermal properties including transport phenomena have been studied. It is proposed to be used as a nominal additive to commercially used electrolytes, ethylene carbonate and di-methyl carbonate mixtures. The comparative performance characteristics of the LIBs in the presence and the absence of this IL additive have been demonstrated with a traditional lithium nickel cobalt manganese oxide cathode (NMC111), a graphite anode, and an ethylene carbonate and di-methyl carbonate (1:1, v/v) electrolyte. It is further demonstrated that use of this electrolyte additive in batteries helps to address some of the major concerns of the conventional electrolytes such as safety issues and cycling performance as well as coulombic efficiency with enhanced discharge capacities.

Electrochemical performance of Li-rich NMC cathode material using ionic liquid based blend polymer electrolyte for rechargeable Li-ion batteries

In this paper, synthesis of lithium rich nickel manganese cobalt oxide cathode material (Li1·2Ni0·6Mn0·1Co0·1O2) and ionic liquid (IL) based blend gel polymer electrolytes (BGPEs) are reported. Li1.2Ni0.6Mn0.1Co0.1O2 cathode material as well as BGPEs are prepared by solution combustion and solution casting technique, respectively. X-ray diffraction (XRD) technique clearly reveals that the cathode material is in pure phase, having well defined layered structure. Thermal, electrical and electrochemical properties of BGPEs are investigated by using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), impedance spectroscopy and linear sweep voltammetry (LSV). It is observed that 70 wt% IL containing BGPE provides maximum Li-ion conductivity (σLi+∼1.1 mS cm−1), thermal (∼250 °C) and electrochemical stability (∼4.3 V vs. Li/Li+). Electrochemical analysis of the cell (Li/70 wt% BGPE/Li1·2Ni0·6Mn0·1Co0·1O2) provides well defined redox peaks corresponding to Ni2+/Ni4+ and it delivers specific discharge capacity of 166 mAh g−1 at 0.1 C-rate and 97% efficiency upto 140 cycle.

Synthesis, characterization and application of a non-flammable dicationic ionic liquid in lithium-ion battery as electrolyte additive

A novel dicationic room temperature ionic liquid, 1,1′-(5,14-dioxo-4,6,13,15-tetraazaoctadecane-1,18-diyl) bis(3-(sec-butyl)-1H-imidazol-3-ium) bis((trifluoromethyl)-sulfonyl) imide has been synthesized and fully characterized. Its thermal and electrochemical analyses along with transport properties have been studied. We propose it as a potential nominal additive to the commonly used conventional organic carbonate electrolyte mixture and study its adaptability in Lithium-ion batteries which are the prime power sources for ultraportable electronic devices. We have compared the performance characteristics of the full cells made without and with this ionic liquid. The cells comprise lithium nickel cobalt manganese oxide cathode, graphite anode and ethylene carbonate - dimethyl carbonate (1:1, v/v + LiPF6) mixture electrolyte with nominal amount of ionic liquid as additive. The major concern with conventional electrolytes such as degradation of the materials inside batteries has been addressed by this electrolyte additive. Additionally, this additive is safer at relatively higher temperature. In its presence, the overall battery life is enhanced and it shows good cycling performance and coulombic efficiency with better discharge capacities (22% higher) after 100 cycles. Even after the increase in current rate from 10 mA/g to 100 mA/g, the cell still retains around 73% of capacity.

Recycling and Direct-Regeneration of Cathode Materials from Spent Ternary Lithium-Ion Batteries by Hydrometallurgy: Status Quo and Recent Developments

The cathodes of spent ternary lithium-ion batteries (LIBs) are rich in nonferrous metals, such as lithium, nickel, cobalt and manganese, which are important strategic raw materials and also potential sources of environmental pollution. Finding ways to extract these valuable metals cleanly and efficiently from spent cathodes is of great significance for sustainable development of the LIBs industry. In the light of low energy consumption, ‘green’ processing and high recovery efficiency, this paper provides an overview of different recovery technologies to recycle valuable metals from cathode materials of spent ternary LIBs. Development trends and application prospects for different recovery strategies for cathode materials from spent ternary LIBs are also predicted. We conclude that a highly economic recovery system: alkaline solution dissolution/calcination pretreatment → H2SO4 leaching → H2O2 reduction → coprecipitation regeneration of nickel cobalt manganese (NCM) will become the dominant stream for recycling retired NCM batteries. Furthermore, emerging advanced technologies, such as deep eutectic solvents (DESs) extraction and one–step direct regeneration/recovery of NCM cathode materials are preferred methods to substitute conventional regeneration systems in the future.

Modeling Thermal Runaway of NMC(1:1:1) Cathodes in Non-Aqueous Electrolytes

This work develops a new modeling framework for decomposition of layered metal oxides in non-aqueous electrolytes. Models based on this framework are appropriate for predictions of thermal runaway in lithium-ion battery systems. It accounts for phase changes with oxygen generation and transport limitations. Effects of particle size, limited electrolyte and state of charge are included. Calorimetry measurements from a variety of literature studies are used to calibrate kinetic rate parameters for nickel manganese cobalt oxide cathodes (LixNi0.33Mn0.33Co0.33O2 or NMC 1:1:1), while other measurements are used to validate performance of the resulting model. This model utilizes a recently published method for predicting the heat of reaction from tabulated thermodynamic data. Acknowledgements: This work was supported by the US Department of Energy Office of Electricity, Energy Storage Program. The authors wish to thank Dr. Imre Gyuk for his support of research advancing safety in stationary energy storage. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government. SAND No: SAND2019-14403 C

Enabling High-Voltage Lithium Metal Batteries by Manipulating Solvation Structure in Ester Electrolyte.

Lithium metal is an ideal electrode material for future rechargeable lithium metal batteries. However, the widespread deployment of metallic lithium anode is significantly hindered by its dendritic growth and low Coulombic efficiency, especially in ester solvents. Herein, by rationally manipulating the electrolyte solvation structure with a high donor number solvent, enhancement of the solubility of lithium nitrate in an ester-based electrolyte is successfully demonstrated, which enables high-voltage lithium metal batteries. Remarkably, the electrolyte with a high concentration of LiNO3 additive presents an excellent Coulombic efficiency up to 98.8 % during stable galvanostatic lithium plating/stripping cycles. A full-cell lithium metal battery with a lithium nickel manganese cobalt oxide cathode exhibits a stable cycling performance showing limited capacity decay. This approach provides an effective electrolyte manipulation strategy to develop high-voltage lithium metal batteries.