Anode Material For Lithium-ion Batteries Research Articles

Electrochemical performance of Cu6Sn5 alloy anode materials for lithium-ion batteries fabricated by controlled electrodeposition.

Combining electrodeposition and heat treatment is an effective method to successfully fabricate Cu6Sn5 alloy materials, in which the S2 alloy electrode is electrodeposited at 1.2 A dm-2 current density with uniform and compact morphology. The characterization results show that monoclinic η'-Cu6Sn5 and hexagonal η-Cu6Sn5 phases fabricated at the appropriate current density exhibit excellent electrochemical performance. The optimal Cu6Sn5 alloy anode material boasts not just a significantly high discharge specific capacity of 890.2 mA h g-1 with an initial coulombic efficiency (ICE) of 73.96%, but also achieves an adequate discharge specific capacity of 287.1 after 50 cycles at 100 mA h g-1. Moreover, the electrodeposited Cu6Sn5 alloy materials also possessed a lower transfer resistance of 42.45 Ω and an improved lithium-ion diffusion coefficient of 2.665 × 10-15 cm2 s-1 at the current density of 1.2 A dm-2. Therefore, preparing the Cu6Sn5 alloy thin-film electrode could be a cost-effective and straightforward method by electrodeposition from cyanide-free plating baths to develop anode components suitable for lithium-ion battery applications.

Batch-Scale Synthesis and Interfacially Enhanced Stability of Silicon Suboxide-Based Anodes toward High-Performance Lithium-Ion Batteries.

SiOx anode materials are among the most promising candidates for next-generation high-energy-density lithium-ion batteries (LIBs). However, their commercial application is hindered by poor conductivity, low initial Coulombic efficiency (ICE), and an unstable solid electrolyte interface. Developing cost-effective SiOx anodes with high electrochemical performance is crucial for advanced LIBs. To tackle these issues, this study utilized APTES as a silicon source and carbon nanotubes (CNTs) as additives to prepare a T-SiOx/C/CNTs composite material with N doping and in situ carbon coating using a "molecular assembly combined with controlled pyrolysis" strategy under mild conditions. The in situ carbon coating, formed by the pyrolysis of organic groups on the molecular precursor, effectively protects the inner SiOx active material. The introduced CNTs enhance electron migration and improve the rigidity of the carbon coating layer. The prelithiated T-SiOx@C/CNTs electrode achieves an ICE of 91.6%, with a specific capacity of 622 mAh g-1 after 400 cycles at 1 A g-1 and 475.8 mAh g-1 after 800 cycles. Full cell tests with commercial NCM811 cathodes further demonstrate the potential of T-SiOx@C/CNTs as a highly promising anode material. This work provides some insights into the rational design of advanced anode materials for LIBs, paving the way for their future development and application.

Polyvinylpyrrolidone-assisted sol–gel synthesis of efficient Li2TiSiO5/C composite anodes for Li-Ion batteries

This study presents the process of developing an effective anode material for lithium-ion batteries (LIBs) by usage of Li2TiSiO5 coated with a thin layer of carbon (LTSO/C). The material was prepared through a sol–gel method, where varying amounts of polyvinylpyrrolidone (PVP) were used as a carbon source during the synthesis process. The physicochemical analysis of the LTSO/C samples indicates that as the amount of PVP used during sol–gel synthesis increases, the particle diameter of LTSO decreases. Furthermore, the analysis shows that a thin amorphous carbon layer is deposited on the LTSO surfaces, along with additional carbon networks between the LTSO particles. Based on the electrochemical analysis conducted to optimize the amount of PVP during synthesis, the resulting LTSO/C composite electrode synthesized with 1 g of PVP exhibits a specific capacity of 274.5 mAh·g−1 at 0.1C after 150 cycles, which is quite close to the theoretical capacity. In addition, this LTSO/C electrode demonstrates exceptional electrochemical performance when operated at high rates, surpassing a discharge capacity of 170 mAh g−1 up to 2C. Therefore, the LTSO/C is an excellent choice for high-performance anode material in LIBs.

Mitigating the capacity fading of silicon nanoparticles through double carbon coatings and cobalt doping

Silicon (Si) is considered a highly promising anode material for lithium-ion batteries (LIBs), attributing to its suitable working potential and high specific capacity. Nevertheless, the enormous volume expansion during the lithiation, poor electron conductivity, and low lithium-ion (Li+) diffusion rate limit the application of Si anodes. Here, we design a novel single carbon layer and carbon nanotubes (CNT) coated Si nanoparticle (Si NP@C@CNT composites), in which the single carbon layer derived from citric acid separates between Si nanoparticle (Si NP), effectively avoiding the aggregation of Si NP, while the external carbon framework (CF) composed of CNT boosts the electrical contact between Si NP. Such micro-morphology structure can reduce the stresses during lithiation and promote the formation of stable solid electrolyte interface. Besides, the metallic cobalt (Co) and CNT can effectively enhance electrode conductivity and promote rapid electron transfer. The electrochemical testing results indicate that Si NP@C@CNT anode presents faster electrochemical reaction kinetics with excellent cycle stability (1055.1 mAh g−1 after 300 cycles at 0.5 A g−1) and rate performance (809.9 mAh g−1 at 5 A g-1). The special capacities and capacity retention of Si NP@C@CNT composites are 885.3 mAh g−1 and 85.9 % after 1000 cycles at 1 A g−1. In addition, the constructed full-cell NCM811// Si NP@C@CNT shows well reversible capacity. This research provides a novel idea for Si -based anode with excellent cycling stability, high electron transfer and fast Li+ diffusion ability for LIBs.

Synergetic effects of S, N co-doping and surface concave-pores rich in lotus-leaf-like carbon nanosheets enabled threefold lithium storage mechanisms

Carbon-based materials based on structural and dimensional optimization are appealing as anode materials in lithium-ion batteries (LIBs). However rational design of high-efficiency low-dimensional carbon-based electrodes is still challenging. Therefore, a synthesis strategy based on Schiff base reaction has been devised for S, N co-doped and surface-enriched concave pores coupled with two-dimensional lotus-leaf-like carbon nanosheets (S, N-SCP/LCN). Experimental and theoretical results disclose that the synergetic effect of S, N co-doping and surface concave pores synergistically contribute to the improved lithium storage efficiency. The numerous concave pores within the defective carbon substrates significantly enhance the specific surface area and boost the quantity of active sites. Furthermore, S, N co-doping induces additional surface and structural defects and widens the crystallographic spacing. Herein, the formed threefold lithium storage mechanisms work synergistically to increase the active lithium storage sites and ion diffusion channels, promoting ion diffusion and charge transfer during lithium storage. As expected, the S, N-SCP/LCN exhibits remarkably high lithium storage capacity (1250 mAh/g at 0.1 A/g) and exceptional rate performance (445.65 mAh/g at a high rate of 10 A/g).

Benchmarking the Match of Porous Carbon Substrate Pore Volume on Silicon Anode Materials for Lithium-Ion Batteries.

Silicon (Si) is one of the most promising anode materials for high-energy-density lithium-ion batteries. However, the huge volume expansion hinders its commercial application. Embedding amorphous Si nanoparticles in a porous carbon framework is an effective way to alleviate Si volume expansion, with the pore volume of the carbon substrates playing a pivotal role. This work demonstrates the impact of pore volume on the electrochemical performance of the silicon/carbon porous composites from two perspectives: 1) pore volume affects the loadings of Si particles; 2) pore volume affects the structural stability and mechanical properties. The smaller pore volume of the carbon substrate cannot support the high Si loadings, which results in forming a thick Si shell on the surface, thereby being detrimental to cycling stability and the diffusion of electrons and ions. On top of that, the carbon substrate with a larger pore volume has poor structural stability due to its fragility, which is also not conducive to realizing long cycle life and high rate performance. Achieving excellent electrochemical performances should match the proper pore volume with Si content. This study will provide important insights into the rational design of the silicon/carbon porous composites based on the pore volume of the carbon substrates.

In-situ synthesis of porous Co/MnO@C with low crystallinity as advanced anode materials for lithium-ion batteries

In-situ synthesis of porous Co/MnO@C with low crystallinity as advanced anode materials for lithium-ion batteries

Amorphous AlPO4 Layer Coating Vacuum Thermal Reduced SiOx with Fine Silicon Grains to Enhance the Anode Stability.

Micrometer-sized silicon monoxide (SiO) is regarded as a high-capacity anode material with great potential for lithium ion batteries (LIBs). However, the problems of low initial Coulombic efficiency (ICE), poor electrical conductivity, and large volume change of SiO inevitably impede further application. Herein, the vacuum thermal reduced SiOx with amorphous AlPO4 and carbon double-coating layers is used as the ideal anode material in LIBs. The vacuum thermal reduction at low temperature forms fine silicon grains in the internal particles and maintains the external integrity of SiOx particles, contributing to mitigation of the stress intensification and the subsequent design of multifunctional coating. Meanwhile, the innovative introduction of the multifunctional amorphous AlPO4 layer not only improves the ion/electron conduction properties to ensure the fast reversible reaction but also provides a robust protective layer with stable physicochemical characteristics and inhibits the volume expansion effect. The sample of SiOx anode shows an ICE up to 87.6% and a stable cycling of 200 cycles at 1 A g-1 with an initial specific capacity of 1775.8 mAh g-1. In addition, the assembled pouch battery of 1.8 Ah can also ensure a cycling life of over 150 cycles, demonstrating a promising prospect of this optimized micrometer-sized SiOx anode material for industrial applications.

The Effect of TiO2 on the Electrochemical Performance of Sb2O3 Anodes for Li-Ion Batteries

Antimony (Sb) and its composites have been recognized as potentially good anode materials for lithium-ion batteries (LIBs) due to their relatively high theoretical capacity of 660 mAh g−1 and to their low cost. However, Sb-based anodes suffer from a high-volume change during the lithiation/delithiation process that results in capacity fading and anode degradation after prolonged charge/discharge cycles. To address this issue, Sb2O3/TiO2 nanocomposite electrodes can be synthesized and used as anodes for LIBs with high capacity and good electrochemical stability. In the present work, TiO2@Sb2O3 composites with different (TiO2:Sb2O3) ratios of 0:1, 1:1, 1:4 and 3:1 were synthesized and directly used as anode materials for LIBs. The electrochemical performance of the TiO2/Sb2O3 composite anode with different ratios of TiO2 to Sb2O3 was evaluated by galvanostatic charge/discharge, rate performance and cyclic voltammetry. The 3:1 (TiO2:Sb2O3) composite anode delivered the highest capacity compared to those of the TiO2, SbO3, 1:1 (TiO2:Sb2O3) and 1:4 (TiO2:Sb2O3) electrodes. The TiO2@Sb2O3 composite anode with a 3:1 ratio exhibited a stabilized capacity of 536 mAh g−1 after 100 cycles at 100 mA g−1 and showed excellent rate performance, with current densities between 50 and 500 mA g−1. The improved electrochemical performance was attributed to the synergistic effect of TiO2 (i.e., the coating of Sb2O3 with TiO2) on reducing the volume change of the Sb anode material after prolonged charge/discharge cycles and on maintaining a stable interface between the electrolyte and the composite electrode material.

Comprehensive Investigation of the Crystal Structure of Cation-Disordered Li3VO4 as a High-Rate Anode Material: Unveiling the Dichotomy between Order and Disorder.

This study investigates mechanochemical synthesis and cation-disordering mechanism of wurtzite-type Li3VO4 (LVO), highlighting its promise as a high-performance anode material for lithium-ion batteries and hybrid supercapacitors. Mechanochemical treatment of pristine LVO using a high-energy ball mill results in a "pure cation-disordered" LVO phase, allowing for meticulous analysis of cation arrangement. The X-ray and neutron diffraction study demonstrates progressive loss of order in LVO crystal with increasing milling duration. High-resolution transmission electron microscopy reveals disrupted lattice fringes, indicating cationic misalignment. Pair-distribution function analysis confirms loss of cation arrangements and the presence of short-range order. Combination of these multiple analytical techniques achieves a comprehensive understanding of cation regularity and clearly demonstrates order/disorder dichotomy in cation-disordered materials, ranging from short (<8 Å) to middle-long range (8-30 Å), using an integrated superstructure model of the cation-disordered LVO crystals. Electrochemical testing reveals that mechanochemically treated LVO exhibits superior rate capability, with a 70% capacity retention at a high current density of 50C-rate. Lithium diffusion coefficient measurements demonstrate enhanced lithium-ion mobility in the mechanochemically treated LVO, attributed to cation-disordering effect. These findings provide valuable insights into mechanochemical cation-disordering in LVO, presenting its potential as an efficient anode material for lithium-ion-based electrochemical energy storage.

Computational Insights into the Influence of Surface Functionalization Groups on Zirconium Carbide MXenes as Anode Materials for Lithium-Ion Batteries

Computational Insights into the Influence of Surface Functionalization Groups on Zirconium Carbide MXenes as Anode Materials for Lithium-Ion Batteries

Dual carbon protected ultrafine SnO2 nanoparticles with Sn–C interface for robust lithium storage

Stannic oxide (SnO2)-based lithium-ion batteries (LIBs) have garnered tremendous attention due to their high theoretical capacity and suitable lithium ion insertion potential. However, their widespread applications have been hindered by severe electrode degradation caused by substantial volume expansion of SnO2. In this study, we embedded amorphous carbon encapsulated ultrafine SnO2 nanoparticles on hollow macroporous carbon (AC@SnO2/HMC) as a superior anode material for LIBs. The unique Sn–C interface and dual carbon protection layers effectively mitigated SnO2 nanoparticle agglomeration and volume expansion, reinforcing the cycling stability. Additionally, the capacitive contribution from amorphous carbon significantly improved the reversible capacity and rate capability. As such, the resulting AC@SnO2/HMC electrode exhibited high capacity (1828 mAh g−1 after 200 cycles at 0.1 A g−1), excellent rate capability (1017.6 mAh g−1 at 1 A g−1), and outstanding cycling performance (792.1 mAh g−1 after 880 cycles at 2 A g−1), surpassing previously reported SnO2-based anodes. Furthermore, the AC@SnO2/HMC-based Li-ion full cell demonstrated a remarkable capacity of 566.3 mAh g−1 at 0.2 A g−1 after 200 cycles. This study offers valuable insights into the development of advanced SnO2-based anodes for LIBs and beyond, highlighting their potential for future advancements in battery technology.

A Novel Spinel High-Entropy Oxide (Cr0.2Mn0.2Co0.2Ni0.2Zn0.2)3O4 as Anode Material for Lithium-Ion Batteries

In this study, we synthesized spinel high-entropy oxide (HEO) (Cr0.2Mn0.2Co0.2Ni0.2Zn0.2)3O4 nanoparticles by a simple solution combustion method. These particles were investigated for their performance as anodes in lithium-ion batteries. The reversible capacity is 132 mAh·g−1 after 100 cycles at a current density of 100 mA·g−1, 107 mAh·g−1 after 1000 cycles at a current density of 1 A g−1, and 96 mAh·g−1 rate capacity at a high current density of 2 A g−1. The outstanding cycle stability under high current densities and remarkable rate performance can be attributed to the stable structure originating from the high entropy of the material.

Interfacial engineering in SnO2-embedded graphene anode materials for high performance lithium-ion batteries

Tin dioxide is regarded as an alternative anode material rather than graphite due to its high theoretical specific capacity. Modification with carbon is a typical strategy to mitigate the volume expansion effect of SnO2 during the charge process. Strengthening the interface bonding is crucial for improving the electrochemical performance of SnO2/C composites. Here, SnO2-embedded reduced graphene oxide (rGO) composite with a low graphene content of approximately 5 wt.% was in situ synthesized via a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method. The structural integrity of the SnO2/rGO composite is significantly improved by optimizing the Sn–O–C electronic structure with CTAB, resulting a reversible capacity of 598 mAh g−1 after 200 cycles at a current density of 1 A g−1. CTAB-assisted synthesis enhances the rate performance and cyclic stability of tin dioxide/graphene composites, and boosts their application as the anode materials for the next-generation lithium-ion batteries.

Deciphering the degradation mechanisms of nano-Si and micro-SiO anodes in lithium-ion battery full-cells using distribution relaxation times analysis

Silicon (Si) and silicon monoxide (SiO) have attracted great interest as next-generation anode materials for lithium-ion batteries (LiBs) due to their high energy density. However, their commercialization has been hindered by rapid capacity fading, which stems from mechanical degradation (e.g., cracking and delamination) and the aggressive formation of solid electrolyte interphase (SEI) layer. While understanding these degradation mechanisms in batteries necessitates in-operando measurement techniques, very few non-destructive analytical methods have been documented in literature. This paper highlights the effectiveness of combined electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) techniques in performing systematic characterization of LiNi0.6Mn0.2Co0.2O2 (NMC)/nano-Si and NMC/micro-SiO full-cells. The systematic design of experiments enabled the separate deconvolution of anode and cathode aging using symmetrical cells. This approach offered a clear understanding of the overall degradation mechanisms in the full-cells. The major impedance sources in the NMC/nano-Si full-cell were anode contact impedance, resulting from mechanical degradation of Si, and cathode charge transfer impedance, due to significant lithium loss and consequently deeper extraction of lithium ions in NMC. In contrast, micro-SiO anodes exhibited less electrode-level degradation, as evidenced by SEM images and relatively stable impedance behaviors during extended cycling, which strongly corroborate its superior capacity retention (66 % at 300th cycle) compared to that of nano-Si anode in full-cells (26.5 % at 300th cycle).

Carbon-Based 3D Architectures as Anodes for Lithium-Ion Battery Systems.

Graphite, with its exceptional cyclic performance, continues to dominate as the preferred anode material for lithium-ion batteries. However as high-energy application gains momentum, there is growing demand for higher capacities that alloying/de alloying and conversion type anode materials can offer. Despite their potential, these materials are plagued by challenges such as volumetric fluctuations, low conductivities, and poor cyclic stability. Carbon nanostructures, on the other hand, show tremendous promise with their low volume expansion, high ion diffusion rates, and excellent conductivity. Nevertheless, their limited areal and volumetric densities restrict their widespread utilization. To address these limitations, various strategies such as doping, composite formation, and structural modification have been proposed. This article provides a succinct overview of carbon nanomaterials and their electrochemical performance as 3D carbon-based anodes, along with a comprehensive analysis of the strategies employed to overcome associated challenges while evaluating their potential prospects in the field.

A Novel Gelatin Binder with Helical Crosslinked Network for High-Performance Si Anodes in Lithium-Ion Batteries.

Silicon(Si) is a promising anode material for lithium-ion batteries, but its large volume expansion during cycling poses a challenge for the binder design. In this study, a novel gelatin binder is designed and prepared with a helical crosslinked network structure. This gelatin binder is prepared by enzymatic crosslinking and immersion in Hofmeister salt solution, which induces the formation of network and helical secondary structures. The helical crosslinked network structure can be analogous to a spring group system to effectively dissipate the stress and strain caused by the Si expansion. The gelatin binder is further partially carbonized by low-temperature pyrolysis, which improves its conductivity and stability. The Sianode with the optimized gelatin binder exhibits high initial coulombic efficiency, excellent rate performance, and long-term cycling stability. This study provides an innovative approach for the preparation of high-performance Si anodes, namely by controlling the molecular configuration of the binder to significantly improve the cycle stability, which can also be applied to other high-capacity anode materials that suffer from large volume changes during cycling.

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.

Novel nitrogen-doped carbon-coated SnSe2 based on a post-synthetically modified MOF as a high-performance anode material for LIBs and SIBs.

SnSe2 with high theoretical capacity has been identified as an emerging anode candidate for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). However, the rate performance and cycling performance of this material in practical applications are still limited by unavoidable volume expansion and low conductivity. In this work, we designed and synthesized nitrogen-doped carbon-coated SnSe2/C-N composites using 2-aminoterephthalic acid (C8H7NO4) as a nitrogen-containing compound for modification by hydrothermal and vacuum calcination methods to achieve efficient utilization of active sites and optimization of the electronic structure. The carbon skeleton inherited from the Sn-MOF precursor can effectively improve the electronic conduction properties of SnSe2. N-doping in the Sn-MOF can increase the positive and negative electrostatic potential energy regions on the molecular surface to further improve the electrical conductivity, and effectively reduce the binding energy with Li+/Na+ which was determined by Density Functional Theory (DFT) methods. In addition, the N-doped carbon skeleton also introduces a larger space for Li+/Na+ intercalation and enhances the mechanical properties. In particular, the post-synthetically modified MOF-derived SnSe2/C-N materials exhibit excellent cyclability, with a reversible capacity of 695 mA h g-1 for LIBs and 259 mA h g-1 for SIBs after 100 cycles at 100 mA g-1.

A Novel Biogenic Silicon-Based Anode Material for Lithium-Ion Batteries: A Review

A Novel Biogenic Silicon-Based Anode Material for Lithium-Ion Batteries: A Review