Initial Columbic Efficiency Research Articles

The induced formation and regulation of closed-pore structure for biomass hard carbon as anode in sodium-ion batteries

Biomass hard carbon is regarded as an advanced anode materials for sodium ion batteries (SIBs) since it possesses balanced performance including satisfactory specific capacity, suitable operating voltage window and low cost. Although numerous instances of utilizing biomass-derived hard carbon in SIBs have been observed, the unregulated pore structure of these hard carbon materials significantly constrains the electrochemical performance of SIBs, leading to diminished initial Columbic efficiency (ICE) and plateau capacity. Herein, taking a biomass hard carbon derived from waste camellia seed shells (CSSHCs) as a template, we display a correlation between synthesis conditions and pore structure of CSSHCs. CSSHCs are synthesized via a facile route including pre‑carbonization, purifying, mechanical ball-milling and high-temperature carbonization, and it is found that adjusting the secondary calcination temperature can induce the formation of closed pore structure, which is of great benefit to increase the ICE and the plateau-capacity. Besides, it is also proved that the obtained CSSHCs anodes obey a sodium storage mechanism that can be classified as “adsorption-intercalation-pore filling”, which endows SIBs with a competitive electrochemical performance. Specifically, the obtained biomass hard carbons at 1300 °C exhibits the best electrochemical performance among these anodes with the reversible capacity of as high as 270.0 mAh g−1 and a high ICE of 80.1 %, together with an excellent cycle stability (91.0 % capacity retention after 200 cycles at 0.1C, 1C = 300 mA g−1). Therefore, this study provides a significant exploration and raw material support for the further utilization of the waste biomass and sustainable development of the anode materials for the large-scale application of SIBs.

Effect of Electrolytes on Performance of Tire Derived Carbon for Sodium-Ion Batteries

Sodium-ion batteries (SIBs) have recently become prominent in the battery ecosystem due to their low cost and use of earth abundant materials such as Sodium, Manganese, Aluminum, Iron, and Prussian blue (iron cyanide). [1] Graphite is the standard anode used for LIBs but cannot be used in SIBs due to interlayer distance being too small to accommodate Na+ ion. Hard carbons are suitable candidates for SIB due to their low cost, low working potential, high capacity, and ability to be synthesized at lower pyrolysis temperatures. In our past work we have reported a low-cost, scalable waste tire-derived carbon as an anode for SIBs [2]. In this work we test the tire derived carbon with 6 different electrolytes and understand the impact each has on the performance. The best electrolyte was found to be sodium hexafluorophosphate in ethylene carbonate (EC)–ethyl methyl carbonate (EMC) (NaPF6-EC/EMC) which showed a capacity of 108 mAh/g after 200 cycles at charge/discharge rate of C/3. The initial columbic efficiency (ICE) was found to be 52% and to mitigate this problem we tried a scalable contact pre-sodiation method. The pre-sodiation method showed high initial columbic efficiency drastically improving capacity retention of the battery.

Development of Coal-Derived Graphite for Lithium-Ion Batteries

Graphite is one of many critical minerals that are utilized in lithium-ion batteries. The requirements for domestic sourcing of critical minerals used in Li-ion batteries as outlined in the Inflation Reduction Act have generated interest in exploring alternative production methods and feedstocks for critical minerals. An alternative feedstock for the production of graphite that is being evaluated is coal. Coal is an excellent candidate as a feedstock due to its abundance in the United States and its chemical structure.In this poster, the characterization and electrochemical performance of multiple coal-derived graphites will be presented. A focus will be put on linking electrochemical performance to the microstructure of each material. Electrochemical performance data such as initial capacity loss, gravimetric capacity and columbic efficiency will be presented for both coin and pouch cells. The application of the Multi-Species, Multi-Reaction model on coal-derived graphite will also be presented.

(Invited) Novel Q Carbon Anodes for Sodium-Ion Batteries

The main goal of this research is to develop low-cost anodes for sodium-ion batteries. Lack of standard carbon intercalation/insertion anode for sodium-ion batteries has greatly hindered its application. Two types of Q carbons have been studied as a potential anode material for sodium-ion batteries. Q1 carbon exhibits a high initial columbic efficiency of 81% but has a low-capacity retention of less than 60%. Whereas Q2 carbon has a low initial columbic efficiency of 58% but has a high-capacity retention of 81%. Q2 exhibited a stable capacity of 168 mAh/g at a cycling rate of C/3 which is comparable to other high performing hard carbon anodes. This work will discuss in detail about the synthesis procedure, microstructural and electrochemical performance of the Q carbons. This study reports the successful pathway of using Q carbon as a promising anode for sodium ion batteries.ACKNOWLEDGEMENTSThis research was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

Metal Chloride‐Induced Hydrogen Transfer Enables Efficient Conversion of Aromatic Hydrocarbons for Sodium Storage

AbstractThe cost‐effective synthesis of high‐performance hard carbons (HCs) is a key step of sodium‐ion batteries toward practical applications. Considering the rich resource of low‐value aromatic hydrocarbons (e.g., pitch), there is tremendous interesting in its conversion into value‐added HCs. Unfortunately, it still lacks an efficient way for the synthesis, in addition to the time‐consuming oxygen contamination of the carbon framework. Herein, a universal strategy is reported that enables the efficient synthesis of HCs from pitch by modulating hydrogen transfer using metal chlorides. CuCl2 is selected as the model modulator and the effect of different metal chlorides (FeCl3, AlCl3, ZnCl2, and MgCl2) are further explored. Based on material characterizations and density functional theory calculation employing 1‐methylnaphthalene as the model molecule, it shows that the hydrogen capture and chlorination reactions mediated by CuCl2 and FeCl3 are thermodynamically favored, which promote the crosslinking of pitch to form HCs. After optimization, the derived HC exhibits superior performance of reversible capacity of 304.8 mAh g−1 and a high initial Columbic efficiency of 88.4%. These discoveries provide new insights into the synthesis of HCs from aromatic hydrocarbons, facilitating their utilization in electrochemical energy storage.

A Hybrid Structure to Improve Electrochemical Performance of SiO Anode Materials in Lithium-Ion Battery.

The wide utilization of lithium-ion batteries (LIBs) prompts extensive research on the anode materials with large capacity and excellent stability. Despite the attractive electrochemical properties of pure Si anodes outperforming other Si-based materials, its unsafety caused by huge volumetric expansion is commonly admitted. Silicon monoxide (SiO) anode is advantageous in mild volume fluctuation, and would be a proper alternative if the low initial columbic efficiency and conductivity can be ameliorated. Herein, a hybrid structure composed of active material SiO particles and carbon nanofibers (SiO/CNFs) is proposed as a solution. CNFs, through electrospun processes, serve as a conductive skeleton for SiO nanoparticles and enable SiO nanoparticles to be uniformly embedded in. As a result, the SiO/CNF electrochemical performance reaches a peak at 20% the mass ratio of SiO, where the retention rate reaches 73.9% after 400 cycles at a current density of 100 mA g-1, and the discharge capacity after stabilization and 100 cycles are 1.47 and 1.84 times higher than that of pure SiO, respectively. A fast lithium-ion transport rate during cycling is also demonstrated as the corresponding diffusion coefficient of the SiO/CNF reaches ~8 × 10-15 cm2 s-1. This SiO/CNF hybrid structure provides a flexible and cost-effective solution for LIBs and sheds light on alternative anode choices for industrial battery assembly.

Prelithiation of electrodes in lithium-ion capacitors: A review

Lithium-ion capacitors (LICs) are one of the modern state-of-the-art hybrid capacitors, comprising a high potential window and imparting a higher energy density than supercapacitors (SCs). These LICs encompass elevated power density and a longer life span than lithium-ion batteries (LIBs). Preparation of high-performance electrode materials with electrochemically active microstructure and prelithiation are two efficient approaches to fabricate highly efficient LICs. But it comes across as a real dilemma of low initial Columbic efficiency if only microstructure is considered as an efficient way to enhance the performance. Nevertheless, prelithiation plays a crucial role in the manufacturing of LICs, improving the initial Coulombic efficiency and enlarging the voltage window. This paper reviews the recent lithiation approaches for lithium-ion capacitors by providing their methods and discussing their results concerning their energy and power density.

In-situ confining selenium within bubble - like carbon nanoshells for ultra-stable Li-Se batteries.

Lithium-selenium (Li-Se) batteries are promising energy storage devices. However, the long-term durability and high-rate performance of the Se cathode have been limited by significant volume expansion and the troublesome shuttle effect of polyselenides during repeated charging/discharging processes. To revolutionize these issues, we applied a top-down strategy through the in-situ trapping of amorphous Se within bubble-like carbon (BLC) frameworks, which can radically minimize the presence of surface-absorbed Se while enhancing Se loading capacity. This ingenious technique successfully encapsulates all Se species within carbon nanoshells, creating a distinct half-filled core-shell structure known as Se@void@BLC. This in-situ trapping approach ensures the efficient management of Se volume changes during repeated discharge and charge cycles. Moreover, an extraordinary Se loading capacity of up to 65.6 wt% is reached. Using the Se@void@BLC as cathode for Li-Se battery, we achieve a high initial Columbic efficiency of 84.2 %, a high reversible capacity of 585 mAh g-1 , and an ultralow capacity decay of only 0.0037 % per cycle during 4000 cycles at 10 A g-1 .

Controlled roll to roll pre-lithiation by lithium vacuum vapor deposition for high performance silicon based lithium-ion battery

Silicon oxides (SiOx) anode has attracted great interest for high-energy–density lithium-ion battery due to its extremely abundant reserves, low cost, and easy synthesis. Despite these merits, its low initial columbic efficiency (ICE) and poor cycle ability severely hinder it from widely using. Pre-lithiation methods are considered to be the effective strategies to overcome low ICE concerns. However, current pre-lithiation methods are always limited by their own drawbacks, such as complicated process and uncontrollable pre-lithiation degree. In this work, we reported a controlled roll-to-roll pre-lithiation method with lithium vacuum vapor deposition. Our pre-lithiation method can not only achieve controllable and uniform pre-lithiation degree of SiOx anode, but also is a process simplified design appropriate for large-scale applications. The electrochemical performance of our pre-lithiated anode achieved 10 % ICE improvement and much stable cycle, demonstrating promising potential for commercial applications.

Regenerated Ni-Rich Cathode Materials from Spent Li-Ion Batteries by a Closed Loop Process

The demand for rechargeable lithium-ion batteries (LIBs) has increased exponentially since they were first commercialized by Sony in 1991.[1] Due to the high energy density and excellent cycle stability, LIBs have been widespread utilized in electric vehicles and other applications. However, the lifespan of LIBs is limited. Thus, tons of spent LIBs are generated during the recent decades. More importantly, the price of raw materials, including lithium and cobalt salts, for producing LIBs grows significantly.[2, 3] Therefore, recycling these End-of-Life LIBs becomes a non-negligible part in the whole manufacturing process and hydrometallurgical process is the most common recycling method. Here, our group has demonstrated a closed loop recycling process, combining inorganic acid etching and coprecipitation reaction, to produce regenerated Ni-rich cathode materials. The regenerated LiNi0.83Mn0.06Co0.11O2 shows excellent performance: the first cycle discharge capacity is 214.1mAh/g at 0.05C in the voltage range of 2.8 - 4.3V and the initial columbic efficiency is 90.9%. The performance of our regenerated cathode materials is comparable to commercial cathode materials. In order to further optimize the properties of the regenerated LiNi0.83Mn0.06Co0.11O2, different elements, like Al, with various doping or coating methods will be utilized. Manthiram A. A reflection on lithium-ion battery cathode chemistry. Nature Communications 2020; 11(1):1550.Li W, Lee S, Manthiram A. High‐Nickel NMA: A Cobalt‐Free Alternative to NMC and NCA Cathodes for Lithium‐Ion Batteries. Advanced materials (Weinheim) 2020; 32(33):2002718-n/a.Hou J, Ma X, Fu J, Vanaphuti P, Yao Z, Liu Y, et al. A green closed-loop process for selective recycling of lithium from spent lithium-ion batteries. Green Chemistry 2022; 24(18):7049-7060.

Self-Assembled 2D VS2 /Ti3 C2 Tx MXene Nanostructures with Ultrafast Kinetics for Superior Electrochemical Sodium-Ion Storage.

Constructing nanostructures with high structural stability and ultrafast electrochemical reaction kinetics as anodes for sodium-ion batteries (SIBs) is a big challenge. Herein, the robust 2D VS2 / Ti3 C2 Tx MXene nanostructures with the strong Ti─S covalent bond synthesized by a one-pot self-assembly approach are developed. The strong interfacial interaction renders the material of good structural durability and enhanced reaction kinetics. Meanwhile, the enlarged and few-layered MXene nanosheets can be easily obtained according to this interaction, providing a conductive network for sufficient electrolyte penetration and rapid charge transfer. As predicted, the VS2 /MXene nanostructures exhibit an extremely low sodium diffusion barrier confirmed by DFT calculations and small charge transfer impedance evidenced by electrochemical impedance spectroscopy (EIS) analysis. Therefore, the SIBs based on the VS2 /MXene electrode present first-class electrochemical performance with the ultrahigh average initial columbic efficiency of 95.08% and excellent sodium-ion storage capacity of 424.6mAhg-1 even at 10Ag-1 . It also shows an outstanding sodium-ion storage capacity of 514.2mAhg-1 at 1Ag-1 with a capacity retention of nearly 100% within 500 times high-rate cycling. Such impressive performance demonstrates the successful synthesis strategy and the great potential of interfacial interactions for high-performance energy storage devices.

Surface Modification of Micro-Silicon Anode for High-performance Lithium-Ion Batteries

Advanced lithium-ion batteries are urgently needed in consumer electronic products, electric vehicles, and energy storage, while the traditional carbonaceous anode materials with relatively low specific capacity gradually become difficult to meet the practical requirements in the market. Silicon-based anodes are considered one of the most promising alternatives in LIBs with high specific energy due to their considerable theoretical specific capacities. However, the large volume variation and severe surface parasitic reactions still limit the practical application of silicon anode. In this work, to suppress the surface side reactions and great volume changes, the electrochemical inert Li3PO4 is proposed to be coated as the physical barrier between the silicon and electrolyte. The as-coated micro-silicon has been successfully prepared via a facile spray drying method with a low-temperature thermal treatment. Li3PO4 coating layer with high shear modules can not only passivate the surface but also enable to suppression of the severe volumetric expansion and shrinkage of the silicon particle, thus enhancing the initial columbic efficiency and structural integrity of the silicon materials during long-term cycling. The optimized silicon anode with the proper amount of Li3PO4 displays a superior initial columbic efficiency higher than 90% and a highly reversible capacity of 1394 mAh g-1 after charging and discharging 200 times. It is hoped this work should shed light on the modification of high-capacity anode materials.

Stabilized Anionic Redox by Rational Structural Design from Surface to Bulk for Long-Life Fast-Charging Li-Rich Oxide Cathodes.

On account of high capacity and high voltage resulting from anionic redox, Li-rich layered oxides (LLOs) have become the most promising cathode candidate for the next-generation high-energy-density lithium-ion batteries (LIBs). Unfortunately, the participation of oxygen anion in charge compensation causes lattice oxygen evolution and accompanying structural degradation, voltage decay, capacity attenuation, low initial columbic efficiency, poor kinetics, and other problems. To resolve these challenges, a rational structural design strategy from surface to bulk by a facile pretreatment method for LLOs is provided to stabilize oxygen redox. On the surface, an integrated structure is constructed to suppress oxygen release, electrolyte attack, and consequent transition metals dissolution, accelerate lithium ions transport on the cathode-electrolyte interface, and alleviate the undesired phase transformation. While in the bulk, B doping into Li and Mn layer tetrahedron is introduced to increase the formation energy of O vacancy and decrease the lithium ions immigration barrier energy, bringing about the high stability of surrounding lattice oxygen and outstanding ions transport ability. Benefiting from the specific structure, the designed material with the enhanced structural integrity and stabilized anionic redox performs an excellent electrochemical performance and fast-charging property..

Zinc Single-Atom-Regulated Hard Carbons for High-Rate and Low-Temperature Sodium-Ion Batteries.

Hard carbons, as one of the most commercializable anode materials for sodium-ion batteries (SIBs), have to deal with the trade-off between the rate capability and specific capacity or initial Columbic efficiency (ICE), and the fast performance decline at low temperature (LT) remains poorly understood. Here, a comprehensive regulation on the interfacial/bulk electrochemistry of hard carbons through atomic Zn doping is reported, which demonstrates a record-high reversible capacity (546 mAh g-1 ), decent ICE (84%), remarkable rate capability (140 mAh g-1 @ 50 A g-1 ), and excellent LT capacity (443 mAh g-1 @ -40 °C), outperforming the state-of-the-art literature. This work reveals that the Zn doping can generally induce a local electric field to enable fast bulk Na+ transportation, and meanwhile catalyze the decomposition of NaPF6 to form a robust inorganic-rich solid-electrolyte interphase, which elaborates the underlying origin of the boosted electrochemical performance. Importantly, distinguished from room temperature, the intrinsic Na+ migration/desolvation ability of the electrolyte is disclosed to be the crucial rate-determining factors for the SIB performance at LT. This work provides a fundamental understanding on the charge-storage kinetics at varied temperatures.

Synthesis of passively prelithiated SiOx nanoparticles for Li‐ion battery anode

AbstractA new concept of passive prelithiation to SiOx nanoparticles is introduced and evaluated by investigating their nanostructures and electrochemical properties. Specifically, Li is incorporated into SiOx nanoparticles during the nanoparticle synthesis. We obtain Si‐Li‐O‐based nanoparticles, which we call SILIO; these are much larger than SiOx particles and have totally different nanostructures. Due to nanostructures with various phase distributions, SILIO nanoparticles show enhanced electrochemical properties. The initial reversible capacity (IRC) and initial columbic efficiency (ICE) of SILIO nanoparticles are 946 to 1107 mAh/g and 72% to 77%, respectively, while SiOx exhibits 1,064 mAh/g of IRC only with 41.5% of ICE. In addition, the stability of SILIO in the air is evaluated to guarantee no unstable phases such as Li2Ox (x = 0–2) are present in SILIO. Through our findings, we suggest a new nanostructure model composed of crystalline Si, amorphous SiOx, and lithium silicate.

Cobalt oxide based inorganic-organic hybrid composite as novel anodic material for ultra-stable Li-ion battery

Energy demands for modern society with improved life quality are totally based on materials, which are fossils free to overcome the challenges affecting the health and climate. In the present work, a 3D hierarchical composite of Cobalt oxide@Copper Acetate@Benzenetricarboxylate (Co@CuAc@BTC) is prepared by using Cobalt oxide nanoparticles as a base material to act as an efficient anode material for LIBs. The coating of metallic organic frame work (MOF) of BTC and Cu(II)Ac alternatively, was applied through versatile layer-by-layer (LBL) assembly method. Presence of π-conjugated benzene rings in the composite was identified by analysis of FTIR. Face centered cubic crystal structure aligned with crystallographic pattern was confirmed by pXRD analysis. The surface morphology and elemental composition was predicted by SEM-EDS, Specific surface area through BET and the thermal stability through TGA analysis. Nyquist plots show that the charge transfer resistance Rct for composite is lower (377.2 Ω) comparative to Co-oxide Nps (590.2 Ω). Electrochemical studies showed that Co@CuAc@BTC composite, as an active anodic material for LIBs, exhibited a higher discharge capacity of 1380 mA h/g and remarkably good rate performance with a charge capacity of 1060 mA h/g at 100 mA/g with 78% (10% increase comparative to that of Co-oxide Nps) initial columbic efficiency. At 100th cycle material show 97% columbic efficiency with reversible capacity of 1064 mA h/g. outstanding electrochemical performance of Co@CuAc@BTC composite offers an easy, large-scale and low cost route to produce anode materials for LIBs.

A synergetic modification approach toward high capacity Ni-rich cathode materials for next generation lithium-ion batteries

High discharge capacity and low cost of Ni-rich cathode materials make them an ideal candidate for energy storage applications. Here, we report a novel synergetic approach to modify the LiNi0.91Co0.06Mn0.03O2 cathode active material by Li+ conductive Li3BO3 coating and B3+ doping. The crystal structure of synthesized materials is analyzed by XRD and the surface by XPS, FESEM and FETEM. In rate performance test, Li+ conductive coating on modified NCM (LBO-0.05) conduces a superior discharge capacity of 88.6 mAh g−1 at 5C while pristine delivers only 45.8 mAh g−1. LBO-0.05 NCM exhibited the highest initial columbic efficiency (92%) and discharge capacity (215.3 mAh g−1) than the pristine sample (90.7%, 212.6 mAh g−1). At 2C cycling, LBO-0.05 demonstrates improved capacity retention of 79.4% as compared to pristine which shows only 67.3% after 100 cycles. The enhanced electrochemical performance of modified NCM is attributed to multifunctional Li3BO3 coating and B3+ doping.

How to Promote the Industrial Application of SiOx Anode Prelithiation: Capability, Accuracy, Stability, Uniformity, Cost, and Safety

AbstractSiOx anode with high energy density and superior stability is expected to meet the demand of the rapidly developed electric vehicles’ market. And the prelithiation strategy is proved to be crucial for solving the low initial columbic efficiency that severely limited the practical full‐cell energy density. In the past decades, various prelithiation methods have been extensively explored. And a comprehensive evaluation aiming at the scale‐up application is highly deserved and urgent. In this review, combining the existing battery manufacturing process, the reported prelithiation methods are roundly summarized and re‐evaluated based on the capability, control accuracy, environmental stability, uniformity, cost, safety, and compatibility, which provides guidelines for selecting appropriate prelithiation methods in different application fields. Furthermore, the unsolved issues for the manufacture techniques or instrument and the development direction toward industrial application are discussed.

Offsetting Initial Lithium Loss By Pre-Forming SEI Layer on Graphite Surface

The irreversible lithium loss due to the formation of solid electrolyte interphase (SEI) in the initial cycle greatly reduced the overall cell energy density of lithium ion batteries. Cathode prelithiation methods have been widely explored to compensate this lithium loss. However, these cathode additives with high lithium contents inevitable lower the active cathode materials loading. Here we report a facile graphite prelithiation method by pre-forming SEI layers on graphite surface (Pre-SEI graphite) in a flow cell. The Li accommodation in graphite anode could be controlled by the operation of the time and current density in flow cell for the electrochemical SEI formation. As a result, we demonstrate a 10% initial Columbic efficiency increase of the LiFePO4 electrode in a full cell configuration with our Pre-SEI graphite. The electrochemical pre-formation of SEI on graphite offers a novel route to offset initial lithium loss without a sacrifice of active cathode loading.

Investigation and Characterization of in-Situ Polymer Brush SEI Core Shell Layer Effects on Si Anode Material and Its Battery Performance

Silicon is a promising material for lithium-ion batteries due to its super high capacity.1 However, the volume expansion and the pulverization of Si limit its perforamce.2 This study investigates the effect of a polymer brush core-shell structure of Si as an anode material. The polymer brush is designed through Si-C covalent bond of vinyl monomers by thermal hydrosilylation reaction. According to the results, the PBCS structure provides three significant functions on Si particles because of the intramolecular effect of hydrogen bonding with PBCS and binder delivers a good dispersion in the slurry, a mechanical protection during cycling, and excellent ionic conductivity for high-rate tests. Compared with the unmodified electrode (SiNP), the modified electrodes (SiNP-M1 and SiNP-M2) incorporating the PBCS provides better initial columbic efficiency of 87.1% with the first discharge capacity of 1988.9 mAh g-1. The TEM and operando TXM results display that the PBCS structure significantly protects the nano Si from cracking owing to the high elastic function and intramolecular hydrogen bonding effect of the PBCS. Operando X-ray diffraction is also used to provide the phase information of the Si electrodes. With this novel PBCS-Si material, a high energy density lithium-ion battery contains pure Si can be expected. Reference Li, C.; Shi, T.; Li, D.; Yoshitake, H.; Wang, H., Effect of surface modification on electrochemical performance of nano-sized Si as an anode material for Li-ion batteries. RSC Advances 2016, 6 (41), 34715-34723.Gao, Y.; Yi, R.; Li, Y. C.; Song, J.; Chen, S.; Huang, Q.; Mallouk, T. E.; Wang, D., General Method of Manipulating Formation, Composition, and Morphology of Solid-Electrolyte Interphases for Stable Li-Alloy Anodes. J Am Chem Soc 2017, 139 (48), 17359-17367. Figure 1