High-performance Anode Materials Research Articles

A first-principles research on the properties of two-dimensional penta-BP2 as an anode material for both Na and K ion batteries

The escalating demand for large-scale energy storage solutions has sparked significant interest in metal-ion batteries, particularly in the realm of high-performance anode materials. This work explores the potential of penta-BP2 as an anode material for sodium and potassium-ion batteries through first-principles calculations. The two-dimensional metallic structure of penta-BP2 exhibits favorable electrical conductivity, making it an ideal candidate for anode materials. Theoretical analysis reveals that penta-BP2 can adsorb two layers of Na and three layers of K, resulting in high storage capacities of 1105 and 1473 mAh/g, along with low open-circuit voltages of 0.40 and 0.30 V, respectively. These characteristics enable the production of high energy density in sodium and potassium-ion batteries. Additionally, the material's small Young's modulus and low diffusion energy barriers further establish penta-BP2 as a flexible anode material capable of rapid charge/discharge processes.

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.

Understanding the Sodium Storage Behavior of Closed Pores/Carbonyl Groups in Hard Carbon.

Hard carbon (HC) is a promising anode material for sodium-ion batteries. However, the intrinsic relationship between the closed pores/surface groups and sodium storage performance has been unclear, leading to difficulties in targeted regulation. In this study, renewable tannin extracts were used as raw materials to prepare HC anodes with abundant tunable closed pores and carbonyl groups through a pyrolytic modulation strategy. Combining ex situ characterizations reveals that closed pores and carbonyl groups are regulated by the pyrolytic process. Further, it is demonstrated that the plateau region is mainly contributed by the closed pores; highly stable fluorine-rich solid electrolyte interphase compositions are produced through carbonyl-induced interfacial catalysis. The optimized HC anode displays good cycling stability, exhibiting a high reversible capacity (360.96 mAh g-1) at 30 mA g-1 and capacity retention of up to 94% after 500 cycles at 1 A g-1. Moreover, the full battery assembled with Na3V2(PO4)3/C demonstrates a stable cycling performance. These findings provide a fresh knowledge of the structural design of high-performance HC anode materials and the mechanism of sodium storage in HC.

Highly stable silicon oxycarbide all-solid-state batteries enabled by machined learning accelerated screening of oxides and sulfides electrolytes

Traditional trial–error approach severely limits and restricts rapid development of high-performance anode and electrolytes materials, searching huge parameters space of various anode-solid electrolyte interfaces in an effective and efficient way is the key issue. Here, a novel computational strategy combining machine learning and first-principles is proposed to achieve efficient high-throughput screening of oxides and sulfides electrolytes for highly stable silicon oxycarbide all-solid-state batteries. First-principles calculations demonstrate significant compact of material type and elemental doping on interfacial compatibility between silicon oxycarbide and various electrolytes. By proposing several novel descriptors including interfacial adhesion and formation energies of frozen system with low computation cost, the amounts of demanded trainings data are significantly reduced. Gradient-boosted regression tree model shows low mean absolute errors of 0.09 and high R2 value of 0.99 for the prediction of interface formation energy, demonstrating ultrahigh accuracy and reliability of the algorithm. The present work discovers a series of uninvestigated stable anode-solid electrolytes interfacial couples for further experimental preparation.

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.

Adding CNTs into Anthracite towards High Performance Anode Materials for Lithium Ion Batteries

AbstractCommercial graphite anodes face the problems of high preparation temperature and limited specific capacity in lithium‐ion batteries (LIBs). Amorphous carbon anode materials are prepared at low temperatures and have abundant sources and modes of preparation. As a low‐cost carbon source material, anthracite has a practical application value in storing lithium as anode electrodes of LIBs. However, the capacity is not enough to meet the present increasing demand. We added CNTs to enhance the performance of anthracite‐based carbon anodes. The addition of CNTs significantly improves the electrical properties of amorphous carbon anode materials due to their good electronic conductivity. This anthracite‐based carbon with CNTs (A−C) anode displays a specific cycling capacity of 360 mAh ⋅ g−1 at the current density of 200 mA ⋅ g−1 after 200 cycles in LIBs. We believe that the work has far‐reaching significance for improving the practicability of amorphous carbon anode materials.

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.

Sustainable conversion of vine shoots and pig manure into high-performance anode materials for sodium-ion batteries

Sodium-ion batteries (SIBs) are considered promising candidates for future grid energy storage, with hard carbons emerging as key commercial anode materials. This study presents a novel approach to synthesize N-doped hard carbons via co-hydrothermal treatment of vine shoots and pig manure and subsequent thermal annealing of the resulting hydrochar. This method enhances the development of micro- and ultra-microporosity in the synthesized hard carbons, with nitrogen, and to a lesser extent phosphorus and sulfur, introduced as doping elements. Furthermore, the incorporation of hydrochloric acid during the hydrothermal step promotes biomass hydrolysis, leading to increased mesoporosity and the formation of microsphere clusters. In the realm of electrochemical performance, an investigation into various ester- and ether-based electrolytes has revealed NaPF6 in diglyme as the best formulation, thanks to its thinner and more stable solid electrolyte interface (SEI). Using this electrolyte, the best-performing electrode showed an initial Coulombic efficiency (ICE) of 73 %, with reversible capacities of 239, 180, 86, and 57 mAh g−1 at 0.1, 1, 5, and 10 A g−1, respectively. In addition, the electrode exhibited a remarkable capacity retention of 88 % after 250 cycles as well as a compatible behavior when paired with a NVPF-based cathode.

Interfacial post-heterojunction construction in Mn-doped NiS2 for realizing fast and stable sodium storage

Sodium-ion batteries (SIBs) are considered as ideal energy storage devices. However, sluggish kinetics and mechanical instability of electrode materials hinder the development of SIBs in practical application. It is necessary to design a high-performance anode material for fast and stable sodium storage. Herein, Mn-doped NiS2 with a post-heterojunction (M−NS/C-2) is prepared. The electrochemical performance is improved by the synergistic effect of Mn-doping and post-heterojunction interface construction. On the one hand, Mn-doping enlarges the lattice spacing of NiS2 to accommodate sodium ions, moreover, the stacked morphology with interlamellar void influenced by doping provides a structural buffer and dominant pseudo-capacity. On the other hand, Cu7.2S4 is formed in ether electrolyte for the reaction of polysulfide and copper current collector, which grafts active material onto the copper current collector, reinforcing mechanical supporting. Further, the post-heterojunction interface formation between NiS2 and Cu7.2S4 in the cyclic process can be promoted by Mn-doping, boosting electron transfer to facilitate rapid kinetics. Thus, M−NS/C-2 displays good rate performance (497.9 mAh/g even at 10 A/g) and superior cycling stability (390.4 mAh/g after 20,000 cycles at 10 A/g with 0.0013 % attenuation per cycle). The M−NS/C-2|| Na3V2(PO4)3 full cell shows cyclic performance of 241.5 mAh/g after 100 cycles at 1 A/g.

A Strategy for Anode Recovery and Upgrading by In Situ Growth of Iron-Based Oxides on Microwave-Puffed Graphite

Faced with the increasing volume of retired lithium-ion batteries (LIBs), recycling and reusing the spent graphite (SG) is of great significance for resource sustainability. Here, a facile method for transforming the SG into a carbon framework as well as loading Fe2O3 to form a composite anode with a sandwich structure is proposed. Taking advantage of the fact that the layer spacing of the spent graphite naturally expands, impurities and intercalants are eliminated through microwave thermal shock to produce microwave-puffed graphite (MPG) with a distinct three-dimensional structure. Based on the mechanism of microwave-induced gasification intercalation, a Fe2O3-MPG intercalation compound (Fe2O3-MPGIC) anode material was constructed by introducing iron precursors between the framework layers and subsequently converting them into Fe2O3 through annealing. The Fe2O3-MPGIC anode exhibits a high reversible capacity of 1000.6 mAh g−1 at 200 mA g−1 after 100 cycles and a good cycling stability of 504.4 mAh g−1 at 2000 mA g−1 after 500 cycles. This work can provide a reference for the feasible recycling of SG and development of high-performance anode materials for LIBs.

A Strategy for Anode Recovery and Upgrading by In Situ Growth of Iron-Based Oxides on Microwave-Puffed Graphite.

Faced with the increasing volume of retired lithium-ion batteries (LIBs), recycling and reusing the spent graphite (SG) is of great significance for resource sustainability. Here, a facile method for transforming the SG into a carbon framework as well as loading Fe2O3 to form a composite anode with a sandwich structure is proposed. Taking advantage of the fact that the layer spacing of the spent graphite naturally expands, impurities and intercalants are eliminated through microwave thermal shock to produce microwave-puffed graphite (MPG) with a distinct three-dimensional structure. Based on the mechanism of microwave-induced gasification intercalation, a Fe2O3-MPG intercalation compound (Fe2O3-MPGIC) anode material was constructed by introducing iron precursors between the framework layers and subsequently converting them into Fe2O3 through annealing. The Fe2O3-MPGIC anode exhibits a high reversible capacity of 1000.6 mAh g-1 at 200 mA g-1 after 100 cycles and a good cycling stability of 504.4 mAh g-1 at 2000 mA g-1 after 500 cycles. This work can provide a reference for the feasible recycling of SG and development of high-performance anode materials for LIBs.

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.

What drives the heterogeneous interdiffusion in the Li-Si interfacial region of Si anodes: the Li flux or the Si flux?

The electrochemical reaction in silicon (Si) electrode, accompanying with tremendous volume expansion, causes rapid capacity fade of Li-ion batteries. The Li-ion concentration gradient and structural distribution uniformity influence the inhomogeneous expansion, and the kinetic mechanism of lithiation and interfacial morphology evolvement remains debated. The present study focuses on the dynamics of Li-Si interdiffusion at Si/Li interfaces with various Si-facet orientations and phases using a machine-learning potential. We find that the Si flux from bulk Si to Li-Si interface regions controls the length of Li-Si interdiffusion region. The lithiation length in different Si/Li interface systems exhibits the order of amorphous-Si > crystalline-Si(110) > crystalline-Si(100) > crystalline-Si(111), which agrees with the experimental trend. Our atomic simulations further reveal that the key factor determining the Li-Si interdiffusion is the difference of on-site Si atomic energies between the bulk Si and the Li-Si interface regions. We propose that the large interdiffusion extent is due to a low thermodynamics barrier. Our findings provide insights for the development of high-performance Si anode materials.

In situ synthesis of vertical graphene on porous Si microparticle composite for high-performance anode material

Silicon is capable of delivering a high theoretical specific capacity (4200 mAh g-1) in lithium-ion batteries. However, silicon has poor electrical conductivity, huge volume expansion (∼300%), and unstable solid electrolyte interface (SEI) film, especially for micron-sized silicon particles. We proposed and prepared a novel vertical carbon (VG) coating on a porous silicon (p-Si) microparticle structure, which effectively alleviated the volume expansion and inhibited the interface reaction. The synthesized porous silicon p-Si@VG composite exhibited significant enhanced cycling stability and an excellent reversible capacity of 1563 mAh g-1 (capacity retention of 48.6%) after 200 cycles. The vertical carbon nanosheet structure constructed a three-dimensional conductive network. Therefore, the p-Si@VG composite showed better rate capability and higher lithium-ion diffusion rates. This work is expected to promote the application of micron Si-based composites in lithium-ion batteries.

In situ anchoring in carbon matrix of Bi2O2CO3 as a high-performance anode material for Li-ion batteries

In situ anchoring in carbon matrix of Bi2O2CO3 as a high-performance anode material for Li-ion batteries

A soft carbon materials with engineered composition and microstructure for sodium battery anodes

Sodium-ion batteries (SIBs) have advantages in high sodium resources, providing powerful supplement to the current energy storage system. However, the lack of low-cost and high-performance anode materials still limits its practical application. Herein, a soft carbon anode derived from petroleum coke was successfully synthesized by engineering its composition and microstructure through resin and sodium phosphate compositing with optimal heat treatment process, delivering significant merits over existing composite anode in term of price density, initial Coulombic efficiency (ICE) and carbon yield. Resin helps to increase micropores and inhibit graphitization. Na3PO4 contributes to expand layer spacing and increase reversible groups, meanwhile facilitates the cross-linking of graphite microcrystalline and provides additional sodium supplement with improved ICE and conductivity. Through the synergistic effect by the additives, the optimized sample (P-ONH-1200) exhibits a superior reversible charge specific capacity of 311.9 mAh g−1 with high cycling stability, ICE (90.7 %) in SIBs, and high carbon yield (70 %). It also gains rate performance of 209.7 mAh g−1 at 4 C with 98 % retention after 1000 cycles. The full cell with Na3V2(PO4)3 (NVP) cathode at 1.05 N/P ratio exhibits an excellent stability with a capacity retention of 70 % after 500 cycles at 1 C. It provides a model reference for the microstructure regulation of petroleum coke and a revenue for preparation high-performance soft carbon anode for SIBs.

Silicene/BN heterostructure as high-performance anode material for Mg-ion batteries

Finding a suitable anode material is a key part of the development of Mg-ion batteries (MIBs) to commercialize. In this work, an outstanding Silicene/BN heterostructure was discovered as a candidate anode material for MIBs by using first-principles calculations. The mixed sp2/sp3 orbital hybridization of silicon atoms makes Silicene monolayer easy to adsorb Mg atoms. The introduction of BN monolayer can effectively buffer the structural deformation and improve the electrochemical performances. Compared to pristine Silicene, the Silicene/BN heterostructure exhibited higher structural stability and Mg adsorption capacity. The diffusion of Mg ions in the heterostructure interlayer was easier with a low barrier of 0.160 eV than that on the Silicene monolayer. A comparable low open circuit voltage (0.112 V) was also observed. These results indicated the potential of Silicene/BN heterostructure as a high-performance anode material for MIBs.

Pristine and defective 2D SiCN substrates as anode materials for sodium-ion batteries

Exploring more high-performance anode materials for sodium-ion batteries (SIBs) can smoothly help to build a more sustainable, cleaner, and reliable energy system. This study systematically investigates the potential of 2D pristine SiCN (p-SiCN) and defective (d-SiCN) substrate as candidate materials for SIBs anodes using first-principles computational method. The computational results reveal that the p-SiCN possesses excellent thermal stability and structural cyclical performance, good conductivity, high theoretical specific capacity (1486 mAh·g−1), low diffusion barrier (0.177 eV), and appropriate open-circuit voltage (0.340 V), which allows the p-SiCN substrate more suitable as a potential anode material for SIBs. Furthermore, by investigating the effects of intentionally designed defects on p-SiCN, it is observed that the adsorption energy and diffusion barrier of the Na atom on the d-SiCN substrate increase. Our work demonstrates that investigating the effect of defects on p-SiCN can better explore the properties of anode materials, thus further optimizing the battery performances.

Two-Dimensional TOD-Graphene in a Honeycomb–Kagome Lattice: A High-Performance Anode Material for Potassium-Ion Batteries

Two-Dimensional TOD-Graphene in a Honeycomb–Kagome Lattice: A High-Performance Anode Material for Potassium-Ion Batteries

WITHDRAWN: Novel design of Sn4P3@NxC electrodes and their electrochemical properties

Tin phosphide (SnxPy) is recognized as one of the most promising anode materials for lithium-ion batteries due to its exceptionally high theoretical capacity. However, its application is hampered by significant volume expansion during charge-discharge cycles and inferior electrical conductivity. Proper structural design placs a pivotal role in addressing these challenges, paving the way for high-performance anode materials. This study introduces a nitrogen-doped carbon-coated Sn4P3 nanosphere with a core-shell structure, employing dopamine as the nitrogen source. This innovative approach, utilizing template removal and solid-phase phosphorization, results in both the core and shell acting as active materials, thereby enhancing the volumetric energy density of the electrode. The internal voids within the shell layer mitigate volume expansion during charge-discharge cycles, while the presence of the nitrogen-doped carbon layer maintains the material's stability throughout cycling and improves its electrical conductivity. Electrochemical performance tests confirm the outstanding energy storage capability of this material, with an initial Coulombic efficiency reaching up to 73.6 %. Furthermore, it maintains a stable capacity of 585 mAh g^-1 after 1200 cycles at a current density of 2 A g^-1. This research offers a design paradigm for the development of novel energy storage materials.