Anode Material For Lithium-ion Batteries Research Articles

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.

Adsorption and diffusion behavior of lithium atom on boron-doped armchair graphene nanoribbon- A dispersion-corrected DFT study

In this paper, we study the relevance of considering dispersion interactions in DFT calculations to determine the adsorption behavior of lithium atom(s) on boron-doped armchair graphene nanoribbons. Our findings suggest that substitutional doping with boron atoms makes the AGNR electron-deficient which results in charge transfer from Li to the AGNR. Li atom binds more strongly to B-doped AGNR than pristine AGNR. A stronger Li-C interaction prevents the clustering of Li atoms, thus, inhibiting dendrite growth. The maximum storage capacity of B-doped AGNR reaches to 1261 mAh/g. B-doped AGNR offers a lower diffusion barrier of 0.19 eV to Li atom as compared to pristine AGNR. From the analysis of density of states, it is observed that the semiconducting nature of both pristine and B-doped AGNRs turns into metallic after the adsorption of lithium atom. Our results show that B-doped AGNR can be used as a potential anode material of lithium-ion batteries.

Sequencing-Dependent Impact of Carbon Coating on Microstructure Evolution and Electrochemical Performance of Pre-lithiated SiO Anodes: Enhanced Efficiency and Stability via Pre-Coating Strategy.

Silicon monoxide (SiO) has attracted considerable interest as anode material for lithium-ion batteries (LIBs). However, their poor initial Coulombic efficiency (ICE) and conductivity limit large-scale applications. Prelithiation and carbon-coating are common and effective strategies in industry for enhancing the electrochemical performance of SiO. However, the involved heat-treatment processes inevitably lead to coarsening of active silicon phases, posing a significant challenge in industrial applications. Herein, the differences in microstructures and electrochemical performances between prelithiated SiO with a pre-coated carbon layer (SiO@C@PLi) and SiO subjected to carbon-coating after prelithiation (SiO@PLi@C) are investigated. A preliminary carbon layer on the surface of SiO before prelithiation is found that can suppress active Si phase coarsening effectively and regulate the post-prelithiation phase content. The strategic optimization of the sequence whereprelithiation and carbon-coating processes of SiO exert a critical influence on its regulation of microstructure and electrochemical performances. As a result, SiO@C@PLi exhibits a higher ICE of 88.0%, better cycling performance and lower electrode expansion than SiO@PLi@C. The pouch-type full-cell tests demonstrate that SiO@C@PLi/Graphite||NCM811 delivers a superior capacity retention of 91% after 500 cycles. This work provides invaluable insights into industrial productions of SiO anodes through optimizing the microstructure of SiO in prelithiation and carbon-coating processes.

Robust nitrogen-doped porous carbon encapsulated NiCo2S4 nanodecahedrons for enhanced lithium storage

Transition metal sulfides (TMSs) are attractive anode materials for lithium-ion batteries (LIBs) due to their cost effectiveness, impressive redox properties, and high specific capacity. Among them, NiCo2S4 stands out with a substantial theoretical capacity of 703 mAh g−1 and a high electronic conductivity of 1.25 × 106 S m−1, making it a strong candidate for LIBs. However, NiCo2S4 experiences volume changes and mechanical stress during long-term cycling, leading to structural degradation and rapid capacity decay, which hinders its application. To address these issues, we have developed dodecahedral NiCo2S4 embedded within a nitrogen-doped porous carbon structure (NiCo2S4/NC). The optimal NiCo2S4/NC-300 material exhibits minimum charge transfer resistance, maximum pseudo-capacitive contribution, and exceptional lithium storage performance. At 0.1 A g−1, NiCo2S4/NC-300 exhibits an initial discharge/charge specific capacity of 1730.1/949.4 mAh g−1 and retains a discharge capacity of 454.4 mAh g−1 after 100 cycles. Even at 0.5 A g−1, it delivers an initial discharge/charge capacity of 1301.1/540.1 mAh g−1 with a capacity retention of 81.2 % after 500 cycles. This study presents significant potential for NiCo2S4/NC as a high-performance anode material for LIBs, providing new strategies and insights into the mechanisms for enhancing the performance of TMS-based bimetallic anode materials.

One-step fabrication of binder-free nanoSi-CNT-carbon black/cyclized PAN composite anode for high-performance lithium-ion batteries

Silicon is one of the most promising anode materials for lithium-ion batteries (LIBs) due to its high theoretical capacity. However, its non-conductive nature and significant volume expansion during lithiation pose challenges. In this study, we developed a novel electrode comprising silicon nanoparticles (nanoSi), carbon nanotubes (CNTs), and carbon black (CB) in cyclized polyacrylonitrile (cPAN), referred to as nanoSi-CNT-CB/cPAN. This electrode is fabricated through a one-step thermal process by heating a cast nanoSi-CNT-CB/PAN film on Cu foil at 310 °C. The LIB performance using the nanoSi-CNT-CB/cPAN electrode shows an impressive initial coulombic efficiency of 93.1 % at 0.1 A g−1, a high specific capacity of 2267.2 mAh g−1 at 0.5 A g−1, and a retention of 89.2 % over 390 cycles, achieving 783 mAh g−1 at 5 A g−1. We attribute these results to the fused cPAN, which provides good adhesion to nanoSi, CNTs, CB, and Cu foil, acting as a binder, active material, and ionic conductive medium. The well-dispersed CNTs and CB form an effective conductive network in the electrode. Additionally, the one-step electrode fabrication is a simple and cost-effective process for next-generation Si-based LIBs.

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.

Glucose-assisted solvothermal synthesis of hierarchical micro-nano yolk–shell V2O3 microspheres as an anode material for lithium-ion batteries

To accelerate the development of lithium-ion batteries (LIBs), researchers should urgently exploit next-generation electrodes with high specific capacity, long cycle stability, and excellent rate performance, such as TMOs, silicon-based materials, and alloys. Among all the modification measures, hierarchical micro-nano structure and yolk–shell structure are considered suitable and effective ways to improve the electrochemical performance of those novel materials. Herein, a facile glucose-assisted solvothermal method combined with heat treatment was implemented to synthesize hierarchical micro-nano yolk–shell V2O3. The special-structured material exhibited higher specific capacity, better structure stability, and faster electrochemical kinetics compared with nanosheet-structured and micro-nano-cluster-structured V2O3. When used as an anode for LIB, mnYS-V2O3 delivered high specific capacity of 650.1 ​mA ​h ​g−1 after over 500 cycles at a current density of 100 ​mA ​g−1, with a retention of 93.4 ​%. Moreover, the morphology evolution mechanism of micro-nano structure and yolk–shell structure was investigated in this work, which is beneficial to the design of other mnYS-structured TMOs.

Unraveling the origin of the high reversibility in entropy-stabilized rocksalt-type (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O anodes for lithium-ion storage

Entropy-stabilized rocksalt-type oxides, composed of multiple components, are increasingly recognized as highly promising materials for energy storage applications. In this study, a novel anode material, (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O, demonstrates exceptional reversible specific capacity of 773.4 mAh g−1 even after 200 cycles at 0.1 A g−1. Density functional theory (DFT) analysis reveals superior electrical conductivity of (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O compared to individual oxides like CoO, which has the potential to enhance electronic transfer to improve electrochemical performance. In situ transmission electron microscopy (TEM) observations confirm the reversible crystal structure of rocksalt-type (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O anodes, with only ∼36.8 % volume expansion in four cycles. This investigation offers insights into the (de)lithiation process at a microscopic scale, shedding light on the origins of high reversibility and guiding the design of future high-entropy materials. Entropy-stabilized rocksalt-type (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O oxides exhibit excellent properties, positioning them as promising candidates for lithium-ion batteries (LIBs) anode materials.

Influence of different silicon oxide coatings on the electrochemical properties of anode materials for lithium-ion batteries

Silicon monoxide (SiO) has gained popularity as an anode material for next-generation lithium-ion batteries due to its high theoretical specific capacity, moderate operating potential (0.4 V), low cost, and environmental friendliness. However, its large volume expansion (200 %) during charging and discharging, along with low electrical conductivity, limits its application. SiO@X composites with different cladding coatings were prepared. The results show that the composites with Si and Ti additions have discharge capacities of 1105.62 mAh g−1 and 994.09 mAh g−1 after 100 cycles, respectively, and their capacity retention rates are significantly greater than those of the other three composites.

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.

Self-Assembled Carbon Metal-Organic Framework Oxides Derived from Two Calcination Temperatures as Anode Material for Lithium-Ion Batteries.

Owing to their structural diversity and mesoporous construction, metal-organic frameworks (MOFs) have been used as templates to prepare mesoporous metal oxides, which show excellent performance as anode materials for lithium-ion batteries (LIBs). Co-ZnO/C and Co-Co3O4/C nanohybrids were successfully synthesized based on a precursor of Co-doped MOF-5 by accurately controlling the annealing temperature and atmosphere. Experimental data proved that their electrochemical performance was closely associated with the material phase, especially for Co-ZnO/C, indicating that carbon skeleton materials can maintain a good restoration rate of over 99% after undergoing high-current density cycling. Meanwhile, Co-Co3O4/C nanohybrids showed an exceedingly high reversible capacity of 898 mAh∙g-1 at a current density of 0.1 C after 100 cycles. Their improved coulombic efficiency and superior rate capability contribute to a mesoporous structure, which provides pathways allowing for rapid Li+ diffusion and regulates volume change during charge and discharge processes.

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.

Hierarchical porous microrod In2O3@C@Ti3C2TX composite anode for high-performance lithium-ion batteries

In2O3, employed as an anode, demonstrates exceptional capacity in lithium-ion batteries (LIBs). Nonetheless, its propensity for significant volume expansion results in internal fracturing and reorganization. Two-dimensional double transition metal carbides and nitrides (MXenes), characterized by unique out-of-plane metal atom ordering, exhibit promising electrical properties due to their chemical versatility and intricate structure. However, MXenes' tendency to aggregate or stack into lamellar structures impedes their practical energy storage application. To address these issues, a hierarchical porous microrods In2O3@C@Ti3C2TX (HPMR-In2O3@C@Ti3C2TX) composite anode material was synthesized through electrostatic self-assembly of MIL-68 (In) and Ti3C2TX, followed by carbonization. This synthesis produced continuous one-dimensional microrods with hierarchical porous channels in HPMR-In2O3@C, offering a substantial specific surface area, numerous Li+ storage sites, and enhanced charge transfer rates. Moreover, the interlayer space within Ti3C2TX acts as an electrolyte reservoir, facilitating comprehensive electrochemical reactions and accommodating volume changes during charge-discharge cycles. Consequently, the HPMR-In2O3@C@Ti3C2TX anode exhibited remarkable properties, including a high initial discharge specific capacity of 1406 mAh g-1 at 0.1 C, outstanding cycling performance, and superior rate performance. This research presents a promising direction for the advancement of high-performance anode materials for lithium-ion batteries.

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).

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.