Anode For Lithium-ion Batteries Research Articles

Diagnosis for wetting condition of silicon/graphite (Si/Gr) anode in lithium ion batteries

The need for the longer mileage of electric vehicles has pushed the energy density of lithium ion batteries (LIBs) to their limits. However, enhancing the energy density of LIBs usually causes poor wetting of an anode electrode and its higher ionic resistance (Rion), resulting in lithium (Li) plating. Therefore, it is highly crucial to monitor the anode Rion influenced by wetting condition of the anode during formation process. Here, we introduce the electrochemical indicator to estimate the Rion of the silicon (Si)/graphite (Gr) blended anode in 21700 cylindrical cells depending on its wetting condition, which can be utilized as a screening tool for manufactured cells. It is attributed to the better rate capability of Si compared to Gr in the blended electrode, and their overpotential difference enables the appearance of the diagnostic signal on differential voltage profiles. In practice, we confirm that the proposed indicator has a strong correlation with the overpotential of the Si/Gr anode, and further is related to the cycle performance and whether Li plating occurs or not. Therefore, the indicator can be utilized as a diagnostic tool for inspecting wetting condition of manufactured cells, which can ensure the safety of LIBs.

Expression of Concern: Bimetal-Organic-Framework Derivation of Ball-Cactus-Like Ni-Sn-P@C-CNT as Long-Cycle Anode for Lithium Ion Battery.

Expression of Concern: R. Dai, W. Sun, L.-P. Lv, M. Wu, H. Liu, G. Wang and Y. Wang, "Bimetal-Organic-Framework Derivation of Ball-Cactus-Like Ni-Sn-P@C-CNT as Long-cycle Anode for Lithium Ion Battery," Small 13, no. 27 (2017): 1700521, https://doi.org/10.1002/smll.201700521. This Expression of Concern for the above article, published online on 22 May 2017 in Wiley Online Library (wileyonlinelibrary.com) and has been published by agreement between the journal Editor-in-Chief, Neville Compton, and Wiley-VCH GmbH, Weinheim. The Expression of Concern has been agreed due to inappropriate adjustment of images in this article, specifically in Figures 2E and 2F. The authors have provided some of their raw data, but concerns remain regarding the nature and extent of the editing of images in the article. The editors are satisfied that the conclusions are unaffected, but have decided to issue an Expression of Concern to alert the readers.

Influence of threaded pipe structural parameters on the conveyance of lithium-ion battery anode materials

Particle stratification occurs during the pneumatic conveyance of lithium-ion battery (LIB) anode materials, resulting in an uneven particle size distribution, which affects battery performance. To optimize the conveyance of lithium-ion battery anode material particles and achieve uniform mixing of large and small particles, this study proposes the inclusion of a threaded pipe section and evaluates this structure based on numerical simulations and experimental research. The results indicate that a pitch of 500 mm maximizes the mixing performance enhancement coefficient for the threaded pipe section. Additionally, the mixing performance is best for a channel comprising 4 threaded pipe sections (the enhancement coefficient exceeds 1.6). The final structure with 4 threaded pipe sections, 500 mm pitch, and 4 channels can be used for graphitic anodes in LIBs under conditions of a small pressure drop and excellent mixing performance. This structure also provides uniform particle transportation.

Oxygen vacancy-assisted construction of phosphorus-doped layers to improve the lithium storage performance of T-Nb2O5

T-Nb2O5 is a promising anode material for high power density lithium-ion batteries (LIBs) due to its fast lithium storage capacity and safe lithiation potential. However, its practical application is hindered by its low electronic conductivity. In this work, we improved the electrochemical performance of T-Nb2O5 by surface P-doping and the N-doped carbon substrate. Surface P-doping guided by defects enhances the electronic conductivity of the material, which can synergize with N-doped carbon substrates to form a conductive network and accelerate the lithiation/delithiation process. More importantly, surface P-doping does not destroy the internal crystal structure of the material, ensuring the stability of the Nb2O5 during the charge/discharge process. When used as the anode for LIBs, the Nb2O5-P/N-C exhibits great cycling stability and high-current charge/discharge performance. The specific capacity of Nb2O5-P/N-C exceeds 116 mAh g−1 after 1000 cycles at 1000 mA g−1. This work presents a novel approach to improve the electrochemical performance of T-Nb2O5.

Yolk-shell structured FeS0.5Se0.5@N-doped mesoporous carbon composite as high-performance lithium-ion battery anodes

Transition metal selenides/sulfides are drawing growing attention as promising electrode material for lithium-ion batteries owing to their larger layer spacing and weaker ionic bond compared to transition metal oxides, which are conducive to the intercalation/de-intercalation of Li ions. However, the intrinsic low conductivity and large volume expansion remain a major obstacle for their practical applications. In this work, with the prediction help of the theory model, we design a yolk-shell structure of single-phase ternary FeS0.5Se0.5 and nitrogen-doped mesopore carbon (YS-FeS0.5Se0.5@NMC) via an interfacial co-assembly, followed by one-step selenization and vulcanization. In the composite, single-phase ternary FeS0.5Se0.5 yolk provides more active sites and faster ion/electron transport dynamics than binary Fe2O3, while N-doped mesoporous carbon shell effectively alleviates the large volume expansion of FeS0.5Se0.5, as revealed by in-situ Raman analysis and TEM observation. Meanwhile, the spatial confinement of outer carbon shell also ensures the mechanical stability of the electrode during cycles. These merits endow the YS-FeS0.5Se0.5@NMC anode with a high reversible capacity of 1417mA h/g at 200mA h/g after 120 cycles, and an exceptional rate capability. This work offers an inspired approach for achieving high-performance energy storage electrode materials

Co3O4/CuO Hybrid Hollow Microspheres as Long-Cycle-Life Lithium-Ion Battery Anode.

Co3O4/CuO hybrid hollow microspheres have been successfully prepared via thermal decomposition of CoCu glycolates, whose size can be adjusted by varying the molar ratio of Co2+/Cu2+. As lithium-ion battery (LIB) anode, Co3O4/CuO microspheres exhibited excellent electrochemical performance due to synergistic effects and the hollow structural design, the best Co3O4/CuO sample could maintain a high specific capacity of 1170.4 mAh g-1 after 300 cycles at 1 A g-1, and still retain a capacity of 514.5 mAh g-1 after 1000 cycles at 2 A g-1. Thus obtained Co3O4/CuO hybrid hollow microspheres hold great potential as anode materials for high-performance LIBs.

N, P Co-Doped Hard Carbon Anodes for High-Performance Lithium-Ion Batteries with Enhanced Capacity Retention and Cycle Stability.

Compared to the traditional graphite anode, heteroatom-doped polymer carbon materials have high capacity retention due to their high porosity and porous structure. Therefore, they have great potential for application in lithium-ion battery (LIB) anodes. In this work, an N, P co-doped precursor polymer material (MBPp), synthesized via a one-pot method using bisphenol-A (C-source), melamine (N-source), and 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (P-source). The resulting N, P-co-doped hard carbon materials (MBPs) were prepared at various pyrolysis temperatures, yielding microporous, mesoporous, and macroporous structures. MBP materials demonstrated excellent electrochemical performance as LIB anodes. Notably, MBP-900 achieved a reversible capacity of 262 mAh g-1 at 1000 mA g-1 (in 0.005-2.0 V voltage range) with a capacity retention rate of 97.1 % after 1000 cycles. These findings highlight the significance of MBP materials, which possess numerous defects, large layer gaps, and excellent cycle stability, in advancing the development of polymer anode materials for LIBs.

Perovskite-Type CaVO3 Nanocomposite as High-Performance Anode Material for Lithium-Ion Batteries.

Electric vehicles' rapid development has put higher requirements on the performance of lithium-ion batteries (LIBs). However, the specific capacity of a commercial graphite anode (372 mAh g-1) has become the bottleneck for further improvement. Therefore, it is urgent to develop novel anode materials with superior performance. Herein, we propose crystalline-amorphous dual-phase CaVO3 nanocomposites as LIB anodes. Benefiting from the stable perovskite structure and high conductivity of CaVO3, the nanocomposite follows the intercalation mechanism, resulting in no capacity decay during 5000 cycles. In addition, due to the multielectron transfer provided by amorphous high-valent vanadium oxide, the nanocomposite can provide a high specific capacity of 442.8 mAh g-1 with a suitable average working potential of 0.95 V. The ingenious strategy of constructing nanocomposites through spontaneous oxidation of nanoparticles is expected to be extended to the perovskite oxide family, inspiring the development of more high-performance LIB anodes.

Design of high-capacity composite anode for next generation lithium-ion batteries

Ga is in primary focus for high-capacity anodes of Li-ion batteries (LIBs). Ga-based anode can form Li2Ga with Li at room temperature. Again, decoupling of Li and Ga is easy compared to other high-capacity materials like Si. Low melting temperature, volume changes, and particle agglomeration of Ga-based electrodes in lithiation and delithiation processes are serious challenges toward its commercialization. To overcome these obstacles, we propose a new composite using Mn-doped GaFeP engineered on N-rGO. Three Mn doping ratios (1, 5, and 10 %) were studied for optimization of electrochemical performance. We observed that the 5 % Mn-doped GaFeP/N-rGO delivered an impressive reversible capacity of 1099.9 mAh/g after 200 cycles at 0.3 A/g. Its retention rate capacity (97.6 %) was higher than those of other electrodes. Furthermore, an excellent rate performance and substantial long-term stability of 671.9 mAh/g was achieved at 1.5 A/g after 850 cycles. The reaction mechanism of the high-performance composite electrode is expounded. We hope our study provides new insights and guidelines to the development of Mn-doped Ga-based electrodes with high capacities, minimal volume change, and long cycle stabilities for next-generation LIBs.

Synergetic effect of double-layer coating on silicon nanoparticles for high-performance lithium-ion battery anodes

Silicon has emerged as a potential candidate for next-generation lithium-ion battery (LIB) anodes owing to its exceptionally high theoretical capacity (3580 mAh g−1) and environmental abundance. However, the practical application of Si anodes is severely hindered by low electrical conductivity and a substantial volume expansion rate of over 300 % during the lithiation–delithiation process, leading to rapid capacity degradation. To address these challenges, a double-layer coating strategy was developed and successfully applied to simultaneously enhance the electrical conductivity and mechanical integrity of Si nanoparticles (Si). The double coating layer was designed with an inside conductive pathway and outside robust coverage, which was achieved by encapsulating silicon with a conductive amorphous carbon layer on the silicon surface and coating it with a TiO2 layer (Si@C@TiO₂). These features improved the interfacial and structural stability of the electrodes during repeated cycling. Compared with its respective uncoated and single-coated analogous anodes, the Si, carbon-coated Si (Si@C), and TiO2-coated Si (Si@TiO2) anodes, the Si@C@TiO₂ anode demonstrates exceptional cycling stability and power capability. We believe that this study offers a breakthrough in the design of high-performance Si-based anodes for LIBs.

MgSiO3 doped, carbon-coated SiOx anode with enhanced initial coulombic efficiency for lithium-ion battery

Silicon suboxide (SiOx) is considered as a potential negative material for next-generation lithium-ion battery (LIB). However, the relative low initial coulombic efficiency (ICE) hindered the development of SiOx. Herein, we report a two-step magnesiothermic reduction method to synthesize carbon-coated MgSiO3 doped SiOx particles (MgSiO3–SiOx@C), endowing it with superb properties as the anode of LIB. Comprehensive characterization demonstrates the as-prepared MgSiO3–SiOx@C can increase the ICE and releasing volume expansion. As such, the MgSiO3–SiOx@C nano-architectures exhibit a high ICE of 85.4 %, meanwhile, it also shows relatively stable cycling performance of 759.2 mAh g−1 after 100 cycles at 0.5C with the capacity retention of 59.8 %. The lithium ion full battery with LiNi0.8Mn0.1Co0.1O2 as positive electrode proves the feasibility of its practical application, which delivers a stable reversible capacity of 89.2 mAh g−1 after 150 cycles at 1C with a capacity retention of 62.7 %.

Hierarchical Porous Structured Si/C Anode Material for Lithium-Ion Batteries by Dual Encapsulating Layers for Enhanced Lithium-Ion and Electron Transports Rates.

Silicon (Si) is a promising anode material for next-generation lithium-ion batteries (LIBs) due to its high specific capacity and abundance. However, challenges such as significant volume expansion during cycling and poor electrical conductivity hinder its large-scale application. In this study, the multifunction of sodium polyacrylate (PAAS) utilized to develop a hierarchical porous silicon-carbon anode (Si/SiOx@C) through a simple and efficient method. The hierarchical porous structure successively consists of nano-silicon cores, SiOx encapsulating layers, surrounding space, and phenolic resin-derived carbon shells with carbon chains connecting the SiOx layers and carbon shells in the space. The SiOx nanolayers promote Li⁺ transport, while excess PAAS, removed by washing, generates space for volume expansion, improving cycling performance. Residual carbon chains of PAAS and carbon shells form a conducting carbon network, enhancing electron transport and rate performance. As an anode for LIBs, the composite delivers a high reversible capacity of 685.3 mAh g⁻¹ after 1000 cycles at 1 C with a capacity retention rate of 54.7%. Full cells with the Si/SiOx@C anode and LiNi0.8Co0.1Mn0.1O2 cathode exhibit an excellent capacity retention rate of 96.8% after 200 cycles at 1 C. This work provides a novel approach for the rational design and engineering of advanced LIBs.

High-Quality Epitaxial Cobalt-Doped GaN Nanowires on Carbon Paper for Stable Lithium-Ion Storage.

Due to its distinctive structure and unique physicochemical properties, gallium nitride (GaN) has been considered a prospective candidate for lithium storage materials. However, its inferior conductivity and unsatisfactory cycle performance hinder the further application of GaN as a next-generation anode material for lithium-ion batteries (LIBs). To address this, cobalt (Co)-doped GaN (Co-GaN) nanowires have been designed and synthesized by utilizing the chemical vapor deposition (CVD) strategy. The structural characterizations indicate that the doped Co elements in the GaN nanowires exist as Co2+ rather than metallic Co. The Co2+ prominently promotes electrical conductivity and ion transfer efficiency in GaN. The cycling capacity of Co-GaN reached up to 495.1 mA h g-1 after 100 cycles. After 500 cycles at 10 A g-1, excellent cycling capacity remained at 276.6 mA h g-1. The intimate contact between Co-GaN nanowires and carbon paper enhances the conductivity of the composite. Density functional theory (DFT) calculations further illustrated that Co substitution changed the electron configuration in the GaN, which led to enhancement of the electron transfer efficiency and a reduction in the ion diffusion barrier on the Co-GaN electrode. This doping design boosts the lithium-ion storage performance of GaN as an advanced material in lithium-ion battery anodes and in other electrochemical applications.

Cyclooctatetrathiophene Based MOF-Derived Porous Materials as High-Performance Anode for Lithium-Ion Batteries

Extensive research on anodes with higher capacity than carbon-based materials is driven by the great demand for lithium-ion batteries with higher energy density. However, the cycling stability of high-capacity anodes is usually hindered by significant volumetric changes and structural collapse during the cycling process. Metal-organic frameworks (MOFs) are an emerging class of crystalline materials, and their derivatives are expected as alternative high-capacity anodes, resulting from the merits of easy functionalization and pore engineering. In this study, a novel porous Co-MOF-derived composite anode was prepared by the pyrolysis of a nonporous Co-cyclooctatetrathiophene tetrapyridine (Co-COTTTP) template. X-ray absorption spectroscopy and high-resolution transmission electron microscopy revealed that the precise composition of Co-COTTTP-derived composite anodes with exposed rich redox cobalt oxides active sites, appropriate degree of graphitization, and N, S-doping, which effectively enhanced the electrochemical performance of the composite anodes. Thus, the resulting porous MOF-derived composite anode demonstrated high specific capacity and long cycling stability in the assembled batteries. Specifically, the cells assembled with Co-COTTTP-500 anodes delivered a high reversible specific capacity of 1005.7 mAh/g after 100 cycles at 0.1 A/g and can be cycled steady for 800 cycles at 1 A/g, indicating the structure stability during cell operation. In summary, this study provides a feasible strategy to prepare high-performance MOF-derived anodes and deep understanding for the structure–activity relationship, contributing to the fabrication of high-energy–density lithium-ion batteries.

Synergistic effect of molybdenum dioxide wrapped nitrogen doped carbon nanotubes in binder-free anodes for enhanced lithium storage properties

Molybdenum dioxide (MoO2) is regarded as a potential anode for lithium-ion batteries due to its highly theoretical specific capacity. However, its further application in lithium-ion battery is largely limited by insufficient practical discharge capacity and cyclic performance. Here, MoO2nanoparticles are in-situ grown on three-dimensional nitrogen doped carbon nanotubes (NCNTs) on nickel foam substrate homogeneously using a simple electro-deposition method. The unique structural features are favorable for lithium ions insertion and extraction and charge transfer dynamics at electrode/electrolyte interface. As a proof of concept, the as-synthesized nanocomposites have been employed as anode for lithium-ion battery, exhibiting a reversible and significantly improved discharge capacity of ∼517 mA h g-1at the current density of 150 mA g-1as well as superior cycle and rate performance. The first-principle calculations based on density functional theory and electrochemical impedance spectroscopy results demonstrate a reduced energy barrier of lithium ions diffusion, improved lithium storage behavior, reduced structure collapse, and significantly enhanced charge transfer kinetics in MoO2/NCNTs nanocomposites with respect to MoO2powder. The excellent performance makes as-prepared MoO2/NCNTs nanocomposites promising binder-free anode for high performance lithium-ion batteries. This work also provides important theoretical insights for other state-of-the-art batteries design.

Formicarium-Like Micron Porous Si Synergistically Adjusted by Surface Hard-Soft Nanoencapsulation as Long-Life Lithium-Ion Battery Anode.

Micron porous silicon (MPSi) is a promising lithium-ion battery (LIB) anode that can provide enough space to effectively alleviate the volume expansion and large number of transmission channels to rapidly transport the Li-ions. However, a long-term stable MPSi anode at high current density is still a great challenge. Herein, a double-regulated formicarium like-MPSi composite using the surface hard-soft titanium dioxide-few layered MXene nanotemplate (FMPSi@TiO2@FMXene) was designed and synthesized via an in situ assembly strategy as long-life LIB anode. Such hard-soft TiO2-FMXene nanoencapsulation can collaboratively tune the internal/external stress, inhibit the volume expansion, reduce the interfacial reactions, and improve the electrical conductivity of MPSi, resulting in the great enhancement of structural stability and electrochemical performance in cycling even at high current density. Especially, this FMPSi@TiO2@FMXene anode exhibits a high reversible capacity of 1254.9 and 970.4 mAh/g after 500 cycles at 0.5 and 1 A/g, respectively. Moreover, a full cell is assembled with the FMPSi@TiO2@FMXene anode and commercial LiFePO4 (LFP) cathode, exhibiting a high capacity retention rate of 91.6% in 100 cycles. This work provides an effective surface nanoengineering tactic to obtain the structurally stable MPSi anodes by hard-soft nanotemplate for large-scale and long-term LIB application.

A mechanical strategy of surface anchoring to enhance the electrochemical performance of ZnO/NiCo2O4@nickel foam self-supporting anode for lithium-ion batteries

A mechanical strategy of surface anchoring to enhance the electrochemical performance of ZnO/NiCo2O4@nickel foam self-supporting anode for lithium-ion batteries

Liquid metal-enhanced MoS2 nanocomposite for self-healing colloidal anodes in lithium-ion batteries

Energy storage is pivotal in addressing global energy challenges, with lithium-ion batteries (LIBs) at the forefront. However, their longevity is often limited by anode material degradation. Here, we introduce a novel LM/AgNWs@MoS2 nanocomposite anode material, synthesized via a one-step hydrothermal method, which integrates liquid metal's fluidity with silver nanowires' conductivity and MoS2's rapid lithium-ion diffusion. This composite demonstrates exceptional cycling stability, maintaining 468 mA h g−1 over 2000 cycles at 1 A g−1, and self-heals electrode cracks, offering a significant advancement for LIBs durability and safety. The LM/AgNWs@MoS2 nanocomposite addresses the critical need for durable, self-healing anode materials in LIBs, pushing forward the development of next-generation energy storage solutions.

Mechanically Robust Polyimide Binder Realizes Stable and High Electrochemical Performance for Micro-Silicon Anodes in Lithium-Ion Batteries.

Silicon anodes have been considered one of the most promising candidates for Li-ion batteries due to their high theoretical specific capacity. However, the practical use of silicon anodes is impeded due to side reactions and volumetric change (from 300~400%) charge/discharge process. Binders played a crucial role in Li-ion batteries by effectively mitigating the stress resulting from the volumetric expansion in silicon-based anodes. Herein, we developed a mechanically stable polyimide binder PI-CF3 that introduced trifluoromethyl and hydroxyl groups for commercial microparticular silicon anodes. With a highest Young's modulus of ~921.1 MPa, the binder presented the maximum resilience during the charging and discharging of Micro-Si, integrating the morphology, and reducing the degree to which the electrode disrupted ion and electric pathways. Moreover, -OH and -CF3 groups of the binder could potentially interact with oxide layer at the surface of silicon through hydron bonds, and thereby results in a cross-linking network to improve interface stability during cycling. The as-prepared PI-CF3 binder with excellent intrinsic mechanical and electro-rich groups stabilizes the electrode structure and facilitates fast Li+ transportation. Consequently, micro-Si anode delivered initial specific capacity of 1838 mAh g-1 (at 0.6 A g-1), and at high mass (Si loading = 0.78 mg cm-2) these was retained about 1219 mAh g-1 after 330 cycles (only -0.061% capacity reduction per cycle).

Self-standing TiO₂@CC@PANI core–shell nanowires as flexibles lithium-ion battery anodes

Self-standing TiO₂@CC@PANI core–shell nanowires as flexibles lithium-ion battery anodes