High-capacity Si Research Articles

Effect of Water–Soluble Polyimide (w-PI) Type Binders on the Performance of High-Capacity Silicon Anodes of Lithium-Ion Batteries

In order to enhance rapid charging and driving range for electric vehicles, the high-capacity of lithium-ion batteries (LIBs) is imperative. Commercially available graphite as an anode material has long cycle life, abundance, and low cost. However, it has a limitation in its theoretical specific capacity (372 mAh g−1).To overcome this limitation, much attention has been paid to silicon (Si), which offers a high theoretical specific capacity of 4,200 mAh g−1. Nevertheless, silicon suffers from excessive volume expansion, resulting in issues such as pulverization of active alloy particles, delamination, and the formation of an unstable Solid Electrolyte Interphase layer. This lead to a limitation to use the silicon in large amount in an electrode. A polymeric binder has a critical role in improving the high-capacity Si anode. Conventional polyimide (PI), one of various super-engineering plastics, was applied to the Si anodes, but it is still challenged to water-insolublity and high temperature imidization process around 300 oC. In this study, a water-soluble PI (w-PI) is designed by the polycondensation between dianhydrides and diamine in water environment. In addition, a relatviely low-temperature imidization temperature below 200 oC will be appled by the introduction of dimethylimidazole. This study will briefly outline the direction for implementing a w-PI binder and improving electrochemical performance of high-capacity anode compared to conventional binders such as PVdF and CMC/SBR. Keyword: high-capacity Si anode; dianhydrides and diamine; Polyimide (PI); and water-soluble PI Figure 1

Overlithiation-driven structural regulation of lithium nickel manganese oxide for high-performance battery cathode

Spinel LiNi0.5Mn1.5O4 (LNMO) is a promising cathode material due to its high operation voltage, cobalt free nature and low cost. High energy density of batteries could be realized by coupling LNMO with high-capacity Si based anodes, before which large active lithium loss at the anode should be addressed. Pre-insertion of additional lithium (Li, x) into LNMO, namely overlithaition of LNMO (L1+xNMO) here, becomes a promising approach for active Li compensation. Understanding the materials structure and property evolution of L1+xNMO and their further effect on electrochemical behavior is crucial. Although spinel LNMO could endure a certain amount of extra Li, its excessive insertion could cause degradation in materials structure, interfacial stability and electrochemical performance due to the introduction of large strain, grain boundaries and immoderate reduction of Mn element. L1.4NMO showed a tradeoff between donable lithium-ion capacity and electrochemical cycling stability among the investigated L1+xNMO (x = 0, 0.2, 0.4, 0.6 and 1) samples. L1.4NMO||Si/C cell presented a reversible capacity of 121.7 mAh g−1 and energy density of 429 Wh kg−1, achieving over 50 % improvement than that of LNMO||Si/C cell.

Single-step fabrication of fibrous Si/Sn composite nanowire anodes by high-pressure He plasma sputtering for high-capacity Li-ion batteries

To realize high-capacity Si anodes for next-generation Li-ion batteries, Si/Sn nanowires were fabricated in a single-step procedure using He plasma sputtering at a high pressure of 100–500 mTorr without substrate heating. The Si/Sn nanowires consisted of an amorphous Si core and a crystalline Sn shell. Si/Sn composite nanowire films formed a spider-web-like network structure, a rod-like structure, or an aggregated structure of nanowires and nanoparticles depending on the conditions used in the plasma process. Anodes prepared with Si/Sn nanowire films with the spider-web-like network structure and the aggregated structure of nanowires and nanoparticles showed a high Li-storage capacity of 1219 and 977 mAh/g, respectively, for the initial 54 cycles at a C-rate of 0.01, and a capacity of 644 and 580 mAh/g, respectively, after 135 cycles at a C-rate of 0.1. The developed plasma sputtering process enabled us to form a binder-free high-capacity Si/Sn-nanowire anode via a simple single-step procedure.

Smart Multi‐Layer Architecture Electrodes for High Energy Density Lithium‐Ion Capacitors

AbstractMulti‐layer architectures for use in both negative and positive electrodes are developed through a layer‐by‐layer spray printing approach using complementary material combinations, with the ultimate goal to realize an ideal concept of hybrid lithium‐ion capacitors more fully – delivering attractive energy densities of insertion‐type negative electrodes while preserving outstanding power performances of activated carbon positive electrodes. To sustain advantageous capacities of intercalation anodes even at ultra‐fast charging rates, a thin, discrete layer of high capacity Si was interleaved between high power Li4Ti5O12 electrodes. In a cathode electrode, a sequential layer of insertion‐type LiFePO4 was assembled with a conventional activated carbon layer into a single layer structure, aiming at boosting overall deliverable capacities. The lithium‐ion capacitor comprising the smart multi‐layer architectures of negative and positive electrodes then provided a remarkable energy density of ∼110 Wh/kg with an outstanding power performance of 15 kW/kg.

Cross-Linking Network of Soft–Rigid Dual Chains to Effectively Suppress Volume Change of Silicon Anode

Polyacrylic acid (PAA) is a promising binder for the high-capacity Si anode. However, the one-dimensional structure of PAA could cause the linear molecular chains to slide from the Si surface during the charge-discharge processes, leading to insufficient suppression of the massive volume expansion of the Si anode. Herein, a soft-rigid dual chains' network of PAA-sodium silicate (PAA-SS) was successfully constructed by cross-linking PAA and SS in situ at room temperature. The soft chains of PAA and the rigid chains of polysilicic acid synergistically ensure the enhanced adhesion property and mechanical strength. Therefore, the Si electrode with PAA-SS binder delivers a discharge capacity of 1559 mAh/g after 150 cycles at 4.2 A/g (1C) with an initial Coulombic efficiency of 93.2%. Moreover, the PAA-SS based SiC-500 electrode exhibits a discharge capacity of 441 mAh/g with the capacity retention of 88.2% after 500 cycles at 0.5 A/g, implying the PAA-SS binder's great industrial prospect in Si based electrodes.

Crucial contact interface of Si@graphene anodes for high-performance Li-ion batteries

Despite their extremely high capacity (4200 mA h g−1), the practical application of silicon anodes is still frustrated by their poor cycling performance, resulting from severe volume changes and pulverization of the electrode material. Introducing graphene in silicon is an ideal approach for addressing these issues. Nevertheless, the large size difference between Si and graphene makes high-quality contact difficult to realize, which severely harms the electrochemical performance of Si/graphene composites. Herein, a unique Si@graphene layer structure (p-Si@GN) with an improved contact interface is fabricated by a facile high-pressure method, in which the surfaces of silicon particles are closely covered by graphene layers, restraining the volume changes from multiple angles. The superior structure of the layered p-Si@GN composite exhibits multiple desired features for high-performance Si-based anodes, such as high Li+ storage capacity resulting from high-capacity Si nanoparticles, outstanding electron conductivity due to the formation of a continuous graphene conductive network, and excellent structural stability due to the enhanced protective function of graphene layers with an improved contact interface. Due to these advantages, the p-Si@GN40 anode, prepared under 40 MPa pressure, exhibits a significantly improved capacity of 2096.9 mA h g−1 at a current density of 300 mA g−1, an enhanced rate capability of 706.4 mA h g−1 at 3000 mA g−1, and superior cycling performance with a high capacity retention of 82.6 % after 150 cycles.

Low Temperature Aluminothermic Reduction of Natural Sepiolite to High-Performance Si Nanofibers for Li-Ion Batteries.

Nanostructure silicon is one of the most promising anode materials for the next-generation lithium-ion battery, but the complicated synthesis process and high cost limit its large-scale commercial application. Herein, a simple and low-cost method was proposed to prepare silicon nanofibers (SNF) using natural sepiolite as a template via a low-temperature aluminum reduction process. The low temperature of 260°C during the reduction process not only reduced the production cost but also avoided the destruction of the natural sepiolite structure caused by the high temperature above 600°C in the traditional magnesium thermal reduction process, leading to a more complete nanofiber structure in the final product. For the first time, the important role of Mg-O octahedral structure in the maintenance of nanofiber structure during the process of low-temperature aluminothermic reduction was verified by experiments. When used as an anode for lithium-ion batteries, SNF yield a high reversible capacity of 2005.4 mAh g−1 at 0.5 A g−1 after 50 cycles and 1017.6 mAh g−1 at 2 A g−1 after 200 cycles, remarkably outperforming commercial Si material. With a low-cost precursor and facile approach, this work provides a new strategy for the synthesis of a commercial high-capacity Si anode.

Structural and Morphological Analysis of the First Alloy/Dealloy of a Bulk Si-Li System at Elevated Temperature.

There have been tremendous improvements in the field of Si electrode materials, either by nanoscale or composite routes, and though silicon-containing carbon electrode materials have begun to penetrate the marketplace, the commercial capacities achieved by these cells still fall short of the promise of high capacity Si electrodes. Enabling a cheaper feedstock of Si in the bulk form would make this technology more accessible, though there are many challenges that must be overcome. Whereas other methods utilize nanomaterials and composites to overcome volume expansion and pulverization of a Si electrode, this study explores a thermal route to enable the use of carbon-free bulk Si. To accomplish this, a modified Swagelok cell has been constructed to accommodate high temperatures, corrosive molten salt electrolytes, and a molten lithium electrode to study lithiation of a bulk Si wafer at 250 °C. Scanning electron microscopy, X-ray diffraction, and microcomputed tomography were used to examine morphological and structural changes within the Si upon lithiation and delithiation. It was discovered that semiordered LixSi phases were formed upon lithiation in molten LiTFSI electrolyte at 250 °C, and the higher temperature does not completely mitigate pulverization of the bulk Si electrode.

Strategies for Controlling or Releasing the Influence Due to the Volume Expansion of Silicon inside Si-C Composite Anode for High-Performance Lithium-Ion Batteries.

Currently, silicon is considered among the foremost promising anode materials, due to its high capacity, abundant reserves, environmental friendliness, and low working potential. However, the huge volume changes in silicon anode materials can pulverize the material particles and result in the shedding of active materials and the continual rupturing of the solid electrolyte interface film, leading to a short cycle life and rapid capacity decay. Therefore, the practical application of silicon anode materials is hindered. However, carbon recombination may remedy this defect. In silicon/carbon composite anode materials, silicon provides ultra-high capacity, and carbon is used as a buffer, to relieve the volume expansion of silicon; thus, increasing the use of silicon-based anode materials. To ensure the future utilization of silicon as an anode material in lithium-ion batteries, this review considers the dampening effect on the volume expansion of silicon particles by the formation of carbon layers, cavities, and chemical bonds. Silicon-carbon composites are classified herein as coated core-shell structure, hollow core-shell structure, porous structure, and embedded structure. The above structures can adequately accommodate the Si volume expansion, buffer the mechanical stress, and ameliorate the interface/surface stability, with the potential for performance enhancement. Finally, a perspective on future studies on Si−C anodes is suggested. In the future, the rational design of high-capacity Si−C anodes for better lithium-ion batteries will narrow the gap between theoretical research and practical applications.

Exploiting the capacity merits of Si anodes in the energy-dense prototypes via a homogeneous prelithiation therapy

The practical exploitation of the high-capacity Si anodes suffers from the insufficient cation utilization degree in the energy-dense batteries, which originates from unstable interfacial dynamics, lithiation-induced mechanical stress, and irreversible Li trapping in the alloy intermediates. Herein, we develop a scalable, indirect mechanical calendaring approach to enable the homogeneous prelithiation process, specifically through interpolating an intermediate buffer layer (IBL) with tunable electronic/ionic pathways in-between the lithium foil source and the target high-capacity electrode. Upon the prototype assembly of various prelithiated Si/Graphite anodes (450–1000 mAh g−1 at the constant areal capacity of 4.6 mAh cm−2) and the LiNi0.8Co0.1Mn0.1O2 cathode (NCM811, 23 mg cm−2 for the double-sided electrode), the enhanced Li utilization degree with the highest energy density up to 362 Wh kg−1 could be achieved on the realistic cell level (1.6 Ah pouch model). More encouragingly, the reversible phasic evolution of both the cathode and anode, upon the Li+ inventory replenishment, are real-time tracked by the transmission-mode operando X-ray diffraction (XRD). This IBL-regulated approach is further extended to construct an environmental-adaptive composite film that integrates the metallic Li source, the prelithiation of which could well function even at the extreme humid conditions (long-time shelf life or relative humidity up to 85%).

Tuning Inactive Phases in Si-Ti-B Ternary Alloy Anodes to Achieve Stable Cycling for High-Energy-Density Lithium-Ion Batteries.

Cycle stability improvement of a high-capacity Si anode is a challenge for its wide application in high-energy-density lithium-ion batteries. Active amorphous/nanosized Si embedded in an inactive matrix is a strategy to improve the cycle stability of Si anodes. Ternary Si100-x-yTixBy (5 ≤ y ≤ x ≤ 20) alloys are designed and prepared by ball milling using elemental Si, Ti, and B as starting materials. The formation sequence of inactive phases during mechanical alloying is predicted by an effective heat-of-formation model and verified by microstructural characterization. The local-fine distribution of free amorphous and nanocrystalline Si in the Si100-x-yTixBy is analyzed by confocal μ-Raman spectroscopy. When used as lithium-ion anodes, the capacity and voltage affected by Si and inactive compounds in the Si100-x-yTixBy are concerned to assess their high energy density. Furthermore, the impact of free active Si, the inactive phase, and amorphous Si on the cyclability of Si100-x-yTixBy is studied. The results show that the Si100-x-yTixBy material is a potential anode for high-energy-density Li-ion batteries and could be used to guide the design of multi-component Si-alloy anodes.

Effects of Aniline Tetramer-Co-Acrylic Monomer Grafted to Polysaccharide Backbone As a Conductive and Adhesive Binder for High Capacity Si/C Composite Anodes

Conducting polymers such as polyaniline and polypyrrole have been sometimes described as a potential candidate binder for high silicon anode materials due to its low price, high conductivity, and simple synthesis. The manufacturing process of conducing polymerbased electrodes requires environmental-unfriendly organic solvents such as n-methylpyrrolidone. Due to the drawback, natural polysaccharides blended with the conductive polymers have been often investigated as water-soluble, electronically conductive, and adhesive binder to improve the electrochemical performance of the high-capacity Si anodes. However, the polymer blends are still needed to modify their properties through functionalization with some additional groups, for example, grafting with adhesive monomers and crosslinking for high adhesion strength.In this study, we first prepared aniline tetramer-co-acrylic monomer (AT-Am) by two step polymerization using 4-aminodiphenylamine in acidic solution at ~ 0°C, and then AT was reacted with acryloyl chloride monomer at room temperature for 3 hours to produce AT-Am monomer. Finally, AT-Am and pure acrylamide (AAm) monomers with various weight ratios are grafted and polymerized to the backbone of sodium alginate (Alg). Here AT and AAm have roles of electronic conduction and strong adhesion, respectively. This water-treatable alginate-graft-poly(acrylamide-aniline tetramer) (Alg-g-PAAT) was used as a conductive and adhesive binder for Si/C composite anodes to improve electronic conduction and adhesion ability when compared to natural Alg and Alg-g-PAAm. As a result, the Si/C anode containing Alg-g-PAAT yielded 800 mAh g-1 after 200 cycles with maintaining high columbic efficiency when compared to Alg-g-PAAm and physical blend between Alg-g-PAAm and AT.

A self-driven alloying/dealloying approach to nanostructuring micro-silicon for high-performance lithium-ion battery anodes

The nanostructuring of low-cost micro-sized silicon (mSi) is paramount to achieve the practical viability of deploying high-capacity Si anodes for lithium-ion batteries (LIBs). Conventional methods for converting mSi to nanoporous Si (nSi) involve low product yield, toxic chemical reagents, high energy consumption, etc. Herein, we report a self-driven alloying/dealloying approach to converting mSi to nSi in molten salts, where mSi alloys with Mg powders to generate Mg2Si and, subsequently, the Mg2Si dealloys in a Mg2Si||Sn primary battery with the production of nSi at the negative electrode and the liquid Mg-Sn alloy at the positive electrode. Finally, the Mg-Sn decomposes to Mg gas and liquid Sn through a vacuum-distillation process. Taking the micro-sized Si kerf waste as an example, the pyrolytic carbon-coated (PCC) nSi delivers a capacity of 1080.2 mAh g−1 at 1 A g−1 after 1000 cycles with a capacity retention rate of 83.7%. Furthermore, a fabricated PCC-nSi-2||LiNi0.6Co0.2Mn0.2O2 (NCM622) full cell demonstrates a high energy density of 466 Wh kg−1 as well as good cycling stability for 200 cycles. The improved Li-storage performance is attributed to the synergetic effects of the nanoporous Si and carbon coating. Overall, the self-driven nanostructuring approach along with the vacuum-distillation process maintains a high utilization of mSi, eliminates the use of toxic reagents, and keeps a closed-loop material circle, and thus offers an efficient and green pathway to valorize various mSi for making enhanced lithium-storage anodes.

Vulnerable window of yield strength for swelling-driven fracture of phase-transforming battery materials

Despite numerous experimental and theoretical investigations of the mechanical behavior of high-capacity Si and Ge Li-ion battery anodes, our basic understanding of swelling-driven fracture in these materials remains limited. Existing theoretical studies have provided insights into elasto-plastic deformations caused by large volume change phase transformations, but have not modeled fracture explicitly beyond Griffith’s criterion. Here, we use a multi-physics phase-field approach to model self-consistently anisotropic phase transformation, elasto-plastic deformation, and crack initiation and propagation during lithiation of Si nanopillars. Our computational results reveal that fracture occurs within a “vulnerable window” inside the two-dimensional parameter space of yield strength and fracture energy and highlight the importance of taking into account the surface localization of plastic deformation to accurately predict the magnitude of tensile stresses at the onset of fracture. They further demonstrate how the increased robustness of hollow nanopillars can be understood as a direct effect of anode geometry on the size of this vulnerable window. Those insights provide an improved theoretical basis for designing next-generation mechanically stable phase-transforming battery materials undergoing large volume changes.

(Invited) Stability and Evolution of Solid Electrolyte Interphase on Silicon Anodes

Solid electrolyte interphase (SEI), which forms at the interface between the electrolyte and the electrode, can passivate the surface of graphite anodes and finally facilitate the intercalation of lithium ions into graphite electrodes. However, the concept of only using SEI protects the electrode surface from the reductive electrolyte may be not applicable for silicon (Si) anodes. Different from the intercalation chemistry in graphite anodes, Si anodes experience alloying/dealloying reactions during electrochemical process, leading to phase transformation, morphology and volumetric changes. It generates great complexity in understanding the formation and the structural/composition evolution of the SEI layer during electrochemical process. Considering the high theoretical capacity Si anodes can offer, the investigation of SEI behavior on Si anodes is critical for developing next-generation anode materials. This presentation, which is based on recent results from advanced electrochemical and spectroscopy characterization, systematically elaborates the chemical and physical properties of SEI toward mitigation strategies for stabilizing SEI on Si anodes.

Molecular Layer Deposition of Titanicone over Lithium Silicide Anode

The increasing demands for more advanced consumer electronics, electric vehicles, and stationary facilities call for the next generation of rechargeable batteries with higher specific energy (energy per mass) and energy density (energy per volume) than the current generation of lithium ion batteries (LIBs), which largely use lithium metal oxide (LMO) positive electrodes and graphite negative electrode.Si has become one of the most highly investigated materials for LIB negative electrodes because of its ability to accommodate 3.75 moles of Li per mole of Si (Li15Si4) for a theoretical capacity of 3579 mA h g−1 at room temperature. Despite Si inherent advantages, progress towards a commercially viable Si anode has been impeded by Si rapid capacity fade, poor rate capability, and low coulombic efficiency (CE). Si exhibits volume changes of ~300% upon lithium alloying and de-alloying, leading to material degradation and presenting a major problem for electrochemical performance. This high volume expansion and contraction is too large to be controlled by currently developed coating technologies.As the electrode matrix fractures, the continuous exposure of fresh nano-Si surface to the liquid electrolyte causes parasitic formation of a solid-electrolyte interphase (SEI) leading to irreversible charge loss and low CE. The volume fluctuation, also causes a damage of the electrical contact between Si and the current collector.One of the main front-end strategies established for the realization of such an approach is coating nano-Si particles with flexible materials in order to attempt to accommodate the volumetric changes of the particles. In order to address the challenge of Si dramatic volumetric change, we carried out a surface modification, in which Molecular layer deposition (MLD) was utilized to grow a mechanically robust, flexible coating, producing high-capacity Si nanocomposite anodes.MLD is a thin film deposition technique where hybrid organic–inorganic films are grown by exposing the substrate to subsequent, self-limiting, metal–organic precursor gases. The processes used here is based on TiCl4 as the titanium precursor. TiCl4 is a relatively small molecule, and when combined with the larger organic reactants it leads to high growth rates which are mainly limited by steric hindrance caused by the organic reactants.The composition of the films was studied using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope-Energy-dispersive X-ray spectroscopy (SEM-EDX). Multiple characteristic absorption modes for both carbon and titanium related groups can be observed in the FTIR spectrum, Figure 1. The combination of both the carbon related groups and the Ti absorptions provides evidence for the successful deposition of a hybrid organic–inorganic film containing titanium.The electrochemical performance of the LixSi coated with titanicone used as an anode was investigated by Cyclic Voltammetry (CV). Typical voltammograms of the half cell in the first scan show the formation of the SEI. In the subsequent scans these peaks disappears.We successfully show the deposition of titanicone on LixSi electrode and an initial electrochemical assessment of this electrode. Figure 1

Micrometer-sized ferrosilicon composites wrapped with multi-layered carbon nanosheets as industrialized anodes for high energy lithium-ion batteries

Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercialization. Herein, we use industrial ferrosilicon as low-cost Si source and introduce a facile and scalable method to fabricate a micrometer-sized ferrosilicon/C composite anode, in which ferrosilicon microparticles are wrapped with multi-layered carbon nanosheets. The multi-layered carbon nanosheets could effectively buffer the volume variation of Si as well as create an abundant and reliable conductivity framework, ensuring fast transport of electrons. As a result, the micrometer-sized ferrosilicon/C anode achieves a stable cycling with 805.9 mAh g −1 over 200 cycles at 500 mA g −1 and a good rate capability of 455.6 mAh g −1 at 10 A g − 1 . Therefore, our approach based on ferrosilicon provides a new opportunity in fabricating cost-effective, pollution-free, and large-scale Si electrode materials for high energy lithium-ion batteries. Ferrosilicon composites wrapped with multi-layered carbon nanosheets (MLC) were fabricated. MLC constructs more abundant and reliable conductive network and provides more effective confinement for micrometer-sized Si than conventional carbon coating, which induces superior electrochemical performance.

Stress-relieving defects enable ultra-stable silicon anode for Li-ion storage

Graphite-like coated silicon (Si@G) material has been shown to be only partly useful in addressing the technological problems of high-capacity Si anodes in lithium ion batteries (LIBs). This is because of inevitable and large internal stresses in a Si@G structure induced by instantaneously explosive expansion of Si upon lithiation which destroys the graphitic matrix, and leads to the uncontrolled growth of a solid-electrolyte interphase (SEI) layer, and severe capacity fading. Therefore, it is vital to develop a novel internal-stress-relief strategy for Si@G of the next-generation stable LIBs anodes. Herein, being inspired by a relief valve, we design a nitrogen-doped carbon layer coating on Si nanoparticles (Si@NG) to effectively relief the volume expansion of Si spheres during lithiation. Such homogenous N-doping in each graphitic layer generates uniformly-distributed “hole” defects in the NG network and guarantees a stress relief in the lithiated Si@NG to the maximum extent possible. Therefore, when tested as an anode material for LIBs, Si@NG shows superior cycling stability (1321 mAh·g−1 after 100 cycles at the current density of 2100 mA g−1, about 96.6% capacity retention) and ultra-high initial coulombic efficiency (ICE) of 90.3%.

Preparation of pectin-based dual-crosslinked network as a binder for high performance Si/C anode for LIBs

The modification of pectin polysaccharide through grafting with polyacrylamide and crosslinking is newly proposed as a powerful candidate for a water-soluble binder of high-capacity Si anodes in lithium ion batteries. The grafting of pectin with polyacrylamide enhances adhesion in the electrode and contributes to the good wettability of the carbonate electrolyte. Herein, dual-crosslinking of pectin-g-polyacrylamide was achieved by the ionic crosslinking of pectin with divalent calcium ions and the chemical crosslinking of polyacrylamide with a bisacrylamide. As a result, the dual-crosslinked binder improves further the cycling performance of the Si/C composite anode with a 1.2 mg cm−2 loading, which retains a specific capacity of 729 mAh g−1 after 300 cycles. In contrast, the Si/C electrode containing dual-crosslinked alginate with polyacrylamide shows a specific capacity of 515 mAh g−1 after 300 cycles.

Stable and High-Capacity Si Electrodes with Free-Standing Architecture for Lithium-Ion Batteries

To meet the increasing demands of electric vehicle applications for long ranges, Si-based materials have been intensively investigated as promising candidates for outstanding anodes of lithium-ion ...