High-performance Li-ion Battery Anodes Research Articles

Synergistic structure and oxygen-vacancies engineering of lithium vanadate for kinetically accelerated and pseudocapacitance-dominated lithium storage

The high reversibility, capacity, and safety make lithium vanadate (LVO) an attractive anode to Li-ion batteries, yet they still suffer from the low intrinsic electrical conductivity and ion diffusion rate. Modulating the electronic and crystal structure of materials by vacancies engineering could significantly affect the lithium storage performance. Herein, high concentration of oxygen-vacancies incorporated Li3VO4 nanowires (HLVO) were prepared to make up conductivity and ion diffusion kinetics of LVO as a competitive fast-charging anode. The oxygen-vacancies were derived from the controllable oxidation of local V4+ ions via the thermal treatment, enabling the redistribution of electrons and optimized charge‐transport properties of LVO on the basis of the experimental results and theoretical calculations. The reduced reaction energy barriers, enhanced Li-ion diffusion, improved electrical conductivity, and additional active sites induced by oxygen-vacancies drastically accelerate the redox kinetics, enhancing the capacitive behavior. Thus, the HLVO anode delivers superior electrochemical performance with large specific capacities of 553.8 mA h g−1, exceptional rate capacity of 312.2 mA h g−1 even at 4.0 A g−1 and excellent cycling stability. This finding provides the credence to the prospect of vacancy engineering contributing to develop the matter-of-fact transition metal oxides as high-performance anodes for Li-ion batteries.

Encapsulating biomass-derived SiOx with internal conductive channels in nitrogen-doped flexible carbon cages for high performance Li ion-battery anodes

N-doped flexible porous carbon encapsulated SiOx/C (p-NC/SiOx/C-3) was synthesized using rice husks as both the silicon and carbon source. When utilized as an anode for lithium ion batteries, p-NC/SiOx/C-3 delivers excellent cycling performance.

Cost-Effective Milled Silicon and Exfoliated Graphene Anode for High-Performance Li-Ion Batteries

Lithium-ion batteries play a significant role in modern electronics and electric vehicles. However, current lithium-ion battery chemistries are unable to satisfy the increasingly heightened expectations regarding energy demand and reliability. To boost the overall energy density while ensuring the safety of Li batteries, researchers have focused on developing the battery materials [1]. Silicon has an ultrahigh theoretical capacity and has been regarded as the best choice for next-generation lithium-ion battery anodes, but it also suffers from dramatic expansion during cycling [2]. Hence mitigating volume expansion is one of the main challenges towards developing a successful Si based anodes. Herein, a facile air-controlled electrospray method to directly deposit silicon/graphene (Si/Gr) onto current collectors was described. This method is inspired by an electrospinning process and possesses all the advantages that electrospinning has such as low cost, easy scaling up, and simultaneous solvent evaporation during the spraying process. Cost-effective silicon/graphene (Si/Gr) composite electrodes have been investigated for the multiple benefits of Gr in providing mechanical integrity to buffer the silicon volume expansion while maintaining electronic contact with Si to provide a Li-ion transport pathway and to form a uniform solid electrolyte interface (SEI) layer. Our results revealed a superior battery performance including a capacity of 1000 mAh/g at 2C rates and minor capacity loss during long cycling. The details of synthesis, characterization, and lithium-ion battery results of the hybrid anodes will be presented.

Porous carbon with the synergistic effect of cellulose fibers and MOFs as the anode for high-performance Li-ion batteries

The commercial graphene for Li ion batteries (LIBs) has high cost and low capacity. Therefore, it is necessary to develop a novel carbon anode. The cellulose nanowires (CNWs), which has advantages of low cost, high carbon content, is thought as a good carbon precursor. However, direct carbonization of CNWs leads to low surface area and less mesopores due to its easy aggregation. Herein, the metal-organic frameworks (MOFs) have been explored as templates to prepare porous carbon due to their 3D open pore structures. The porous carbon was developed with the coordination effect of CNWs and MOFs. The precursor of MOFs coordinates with the −OH and − COOH groups in the CNWs to provide stable structure. And the MOFs was grown in situ on CNWs to reduce aggregation and provide higher porosity. The results show that the porous carbon has high specific capacity and fast Li+/electronic conductivity. As anode for LIBs, it displays 698 mAh g−1 and the capacity retention is 85 % after 200 cycles. When using in the full-battery system, it exhibits energy density of 480 Wh kg−1, suggesting good application value. This work provides a low-cost method to synthesize porous carbon with fast Li+/electronic conductivity for high-performance LIBs.

Cobalt Oxide 2D Nanosheets Formed at a Polarized Liquid|Liquid Interface toward High-Performance Li-Ion and Na-Ion Battery Anodes.

Cobalt oxide (Co3O4)-based nanostructures have the potential as low-cost materials for lithium-ion (Li-ion) and sodium-ion (Na-ion) battery anodes with a theoretical capacity of 890 mAh/g. Here, we demonstrate a novel method for the production of Co3O4 nanoplatelets. This involves the growth of flower-like cobalt oxyhydroxide (CoOOH) nanostructures at a polarized liquid|liquid interface, followed by conversion to flower-like Co3O4 via calcination. Finally, sonication is used to break up the flower-like Co3O4 nanostructures into two-dimensional (2D) nanoplatelets with lateral sizes of 20-100 nm. Nanoplatelets of Co3O4 can be easily mixed with carbon nanotubes to create nanocomposite anodes, which can be used for Li-ion and Na-ion battery anodes without any additional binder or conductive additive. The resultant electrodes display impressive low-rate capacities (at 125 mA/g) of 1108 and 1083 mAh/g, for Li-ion and Na-ion anodes, respectively, and stable cycling ability over >200 cycles. Detailed quantitative rate analysis clearly shows that Li-ion-storing anodes charge roughly five times faster than Na-ion-storing anodes.

Core–shell Cu1−x NCo3−y /a-CuFeCo antiperovskite as high-performance anode for Li-ion batteries

Currently, there is an emergent interest in the antiperovskite family of materials in the context of energy applications in view of their distinct and peculiar set of structural and electronic properties. This work examines the surface-modified antiperovskite nitride CuNCo3 as a high-performance anode material for Li-ion storage devices. The antiperovskite CuNCo3 was prepared by the hydrothermal method followed by calcination in the NH3 atmosphere. An amorphous layer on the surface of CuNCo3 (Cu1−x NCo3−y /a-CuFeCo) was also fabricated to enhance its performance as an anode material for Li-ion batteries. The surface-modified Cu1−x NCo3−y /a-CuFeCo material was noted to deliver an extraordinarily high reversible capacity of ∼1150 mAh g−1 at a current density of 0.1 A g−1, whereas the CuNCo3 showed a reversible capacity of ∼408 mAh g−1 at the same current density. The initial capacity of Cu1−x NCo3−y /a-CuFeCo exhibited excellent retention (>62%) even after 350 cycles. A ∼6 nm thin amorphous layer around the surface of pure CuNCo3 helped almost double the specific capacity as compared to the pure CuNCo3 due to the presence of a multi-redox center for Li-ion to react and also concomitantly improved electrical conductivity property. The cyclic stability of the Cu1−x NCo3−y /a-CuFeCo material at a higher current density (0.5 and 1.0 A g−1) was also noticeable. This work opens up new materials routes and promising processing strategies to develop high reversible capacity anodes for alkali ion batteries.

Fe-N-C decorated fibrous network-wrapped biomass SiOx/C with gradient conductive structure for high performance Li-ion battery anodes

Fabrication of high performance silicon-based materials derived from natural biowastes plays a significant role in the green recycling of biomass resources. However, low utilization of organic component and poor lifespan hinders the its large scale applications. Herein, biomass derived SiOx/C-3 composite was encapsulated into Fe-N-C decorated carbon nanofibers network (Fe-N-C/SiOx/C-3) by a facile magnesiothermic reduction combined with electrostatic spinning strategy. The ingenious designed indirect contact biomass carbon/SiO2 interface effectively utilizes the organic components of rice husk and prevents the formation of SiC during reduction process. HAADF-STEM and XPS characterization confirmed the presence of Fe single atoms and the formation of Fe-N coordination bonds. Benefiting from the unique carbonaceous network and catalytic effect of Fe-N-C, the Fe-N-C/SiOx/C-3 exhibit excellent lithium storage properties (832.6 mAh g−1 after 250 cycles at 0.1 A g−1). Even at high current density (1 A g−1), the electrode can still remain a capacity of 602 mAh g−1 after 1000 cycles with capacity retention of 79.4%. The ex-situ SEM and XPS characterizations demonstrated that the gradient structure consisting of inner biomass-derived carbon and flexible carbonaceous networks enhanced the overall conductivity and structural integrity of the composite. Furthermore, the catalytic effect of Fe-N-C facilitates the rapidly formation of stable LiF-rich solid electrolyte interphase (SEI) films during charge/discharge process. The assembled LiFePO4‖Fe-N-C/SiOx/C-3 full cell shows excellent electrochemical performance (106.5 mAh g−1 after 100 cycles at 0.1A g−1), which provides insights into the fabrication of high performance biomass derived silicon based anodes.

Advancements in anode and cathode nanomaterials for high-performance Li-ion batteries

Commercially, lithium-ion batteries are the most popular batteries for electric devices, while energy density and stability have become more important for electric vehicles. Therefore, there is an increased interest in producing advanced lithium-ion batteries with a greater range of electric storage capability and improved electron transfer efficiency. Over the past few years, nanotechnology has been widely applied to enhance the physical properties of materials through the application of surface treatments or the modification of nanostructures. The significant development potential of nanotechnic applications for lithium-ion batteries is the reason for this discussion. There have been several advancements in graphene, carbon nanotubes, silicon-based and other metal-based anodes, lithium cobalt oxide, lithium iron phosphate, and nickel-based cathodes, their fabrication processes and understanding of mechanisms, as well as trends for further improvement of those previously discovered. These advancements have led to the development of batteries with greater capacity and greater performance, better stability, quicker charging times, and a longer cycle life.

Layered GeSe/thermally-reduced graphene oxide composites as efficient anodes for high-performance Li-ion batteries

Due to their layered structure and greater electrical conductivity compared to traditional metal oxides, layered metal selenides have been extensively explored as promising electrode materials for Li-ion batteries. The greatest obstacles to their continued growth, however, are the substantial volume change and particle agglomeration during cycling. In this work, layered GeSe/ thermally-reduced graphene oxide (TRG) composites were successfully synthesized by using a facile shear-force exfoliation approach. When a highly conductive TRG matrix was incorporated with GeSe particles, the resultant GeSe/TRG composite electrode achieved an impressive reversible capacity (>840.1 mAh g−1 at 0.1C), improved rate capability as well as excellent cycling stability. The remarkable improvement in electrochemical performance of the GeSe/TRG composite electrode corresponds to the TRG matrix, which potentially constructs an efficient conductive channel and serves as a flexible mechanical buffer for the restriction of volume expansion and particle aggregation.

Metal oxide- and metal-loaded mesoporous carbon for practical high-performance Li-ion battery anodes

The rapidly expanding Li-ion battery market needs new materials that can satisfy the increasing energy storage demand. Metal oxides and some metals such as tin are viable alternatives to graphite as Li-ion battery anodes, but their low conductivity and large volume change during cycling impose severe challenges that need to be overcome. Confinement of metal oxide and metal nanomaterials within mesoporous carbon (MC) is an effective strategy in this regard, but complex synthesis and nanoparticle aggregation have hindered its application. Herein, we report a facile, scalable and generalized methodology for the room-temperature synthesis of metal oxide and metal nanoparticles within a MC host. The approach has been successfully applied to achieve uniform distribution and prevent aggregation of a large variety of metal oxide and metal nanomaterials in MC support. These nanocomposites were screened as Li-ion battery anodes, and the optimal candidates were shown to be superior to previously reported systems. Our synthesis method was scaled up using commercial MC. The nanocomposites were validated in a high-loading electrode (4 mg/cm2) with a practical voltage range (< 2 V vs. Li+/Li), showing impressive initial Coulombic efficiency (> 100%), and excellent stability (∼ 500 mAh/g after 250 cycles at 0.2 A/g), which was 1.5–2x better than commercial graphite at the same testing conditions. The facile nature, universality and versatility of our approach make it possible to load various metal oxide and metal nanomaterials within different types of MC. These nanocomposites would be of significant interest to different fields, such as energy storage and conversion, sensing, and catalysis.

Candle soot-metal-organic framework-based hierarchical electrode as high-performance anode for Li-ion batteries

Recently, cobalt oxide-based materials have been considered high-performance anode materials. However, cobalt oxide materials display drawbacks such as capacity fade, poor cycle life, and substantial structural strain. In this work, we report a facile synthesis of carbon-cobalt oxide composite to improve the electrode's storage capabilities and cycle life. First, metal–organic framework-based cobalt oxide nano leaves are synthesized by simple coprecipitation followed by calcination. After that, candle soot-derived carbon nanoparticles are uniformly deposited on the cobalt oxide nano leaves by a simple flame synthesis method to form a composite electrode. The fractal-like interconnected carbon nanoparticles improve the electron conducting pathways. In contrast, metal–organic framework-derived porous cobalt oxide nano leaves enhance energy storage abilities through reversible conversion reactions. The superior performance of the composite electrode is established from the galvanostatic charge–discharge experiments. Also, the composite electrode has delivered outstanding specific capacities of 811 and 503 mAh g−1 at 50 and 1000 mA g−1 current densities, respectively. Furthermore, the composite electrode exhibited good cyclic stability at 1000 mA g−1 current density by delivering an excellent specific charge capacity of 490 mAh g−1 even after 400 cycles. Therefore, these superior electrochemical properties confirm the potential applicability in high-performance and stable Li-ion batteries.

Freestanding and Consecutive Intermixed N-Doped Hard Carbon@Soft Carbon Fiber Architectures as Ultrastable Anodes for High-Performance Li-Ion Batteries

Freestanding and Consecutive Intermixed N-Doped Hard Carbon@Soft Carbon Fiber Architectures as Ultrastable Anodes for High-Performance Li-Ion Batteries

Selenium enriched over-oxidized Mo3Se4 decorated MXene as a high-performance Li-ion battery anode material

The anode materials in Li-ion battery (LIB) are key components that define the performance of the cell. We have developed new selenium enriched and over-oxidized Mo3Se4 decorated MXene (Mo3Se4@Ti3C2Tx) composite as a promising anode material for Li-ion battery (LIB). By using selective experimental conditions, Mo3Se4@ Ti3C2Tx was successfully developed with unique structural and morphological features. When being employed as anode material in LIB, Mo3Se4@Ti3C2Tx delivered high stable reversible specific discharge capacity of 1250 mAh/g at 0.1C, which is significantly higher than traditional carbon-based anode materials. In addition, the composite retained 84.53 % of initial specific capacity when the C-rate was increased from 0.1C to 1.5C, implying excellent rate performance. The Mo3Se4@Ti3C2Tx composite also demonstrated remarkable cycling stability with negligible loss after 378 cycles. This exceptional electrochemical performance can be assigned to the exclusive architecture of Mo3Se4@Ti3C2Tx composite, leading to increase in exposure of active Li+ sites and structural stability.

Electrical bridging effects of dual-carbon microsphere frameworks in Si-based composite anodes for high-performance Li-ion batteries

Herein, the successful fabrication of a high-performance Si-based composite Li-ion battery (LIB) anode, comprising a dual-carbon framework of reduced graphene oxide (r-GO) and oxidized single-walled carbon nanohorns (o-NHs), was demonstrated using a simple and scalable spray-drying process followed by heat treatment (h-s-GO/Si/NH). The r-GO nanosheets in the h-s-GO/Si/NH anode acted as a robust spherical framework that facilitated the mechanical and electrical connection between the carbon-coated Si (c-Si) nanoparticles, homogeneous dispersion of c-Si and o-NH nanoparticles, and suppression of the volume expansion and pulverization that occur during lithiation/delithiation. Additionally, the o-NH nanoparticles incorporated in the h-s-GO/Si/NH composite served as electrical bridges between the r-GO nanosheets, resulting in enhanced electrical conductivity and effortless Li-ion shuttling. The h-s-GO/Si/NH composite anode exhibited high electrochemical performance with a very high initial gravimetric charge capacity (2961 mAh g−1 at 0.1 A g−1), stable initial Coulombic efficiency (80.6% at 0.2 A g−1), and high cycling stability (983 mAh g−1 at 0.2 A g−1 after 50 cycles). This study highlights the importance of the effective design of electrically conductive three-dimensional frameworks in Si-based composite anodes, which may contribute to the development of high-performance LIB anode materials.

Engineering a polyaniline nanoneedles-coated multi-layered Co3O4/NiO microsphere as high-performance Li-ion battery anode

High energy-storage Li-ion battery needs a high-capacity anode. However, current graphite-based anode doesn’t meet this requirement, thus developing high performance anode materials is highly needed and significant. Here, we provide a rational engineering of a multi-layered hollow structure combining with surface coating of polyamine (PANI) layer, forming a Co3O4/NiO@PANI hybrid using for Li-ion battery anode. PANI is able to effectively improve the conductivity of active materials; besides, PANI is flexible, which can prevent the collapse of the structure caused by volume-expansion during charge and discharge. The multi-layered morphology improves the utilization ratio of voids inside the conventional hollow structured materials, which is significant to improve capacity in practical applications. The Co3O4/NiO@PANI hybrid-based anode shows a capacity of 1049 mAh g−1 along with a Coulombic efficiency of 99.3% after 100 cycles of 0.2 A g−1. Rate-performance of Co3O4/NiO@PANI exceeds that of the bare Co3O4/NiO. It is believed that the hierarchical structure combining multi-layered hollow morphology with surface coating of conductive polymer presented here would find broad applications for developing high-performance energy-storage hybrids.

Fe2O3/carbon derived from peanut shell hybrid as an advanced anode for high performance lithium ion batteries

Carbon materials derived from biomass behave sustainability, easy availability, low cost and environmentally benign. And Fe2O3 are considered as promising anodes for high-performance Li-ion batteries (LIBs) because of their rich electrochemical properties, higher theoretical capacity (1007 mAh g−1), non-toxicity, high corrosion resistance and safety. However, the high irreversible capacity loss and poor cycling stability of Fe2O3 hinders its commercial applications in LIBs. In this work, we have developed a Fe2O3@C derived from peanut shell composite by two-step hydrothermal method and low-temperature calcination with the assistance of Fe(NO3)3. As an anode for LIBs, the Fe2O3@C composite an excellent electrochemical performance in term of the specific capacity of 1000.8 mAh g−1 at 200 mA g−1 after 100 cycles, and high rate capability of 573.5 mAh g−1 even at 1 A g−1 after 200 cycles. This enhancement could be attributed to the porous carbon matrix combined with Fe2O3 nanoparticles which could increase contact area between electrolyte and active materials, improve conductivity, and accommodate the volume variations via additional void space during cycling. This work may be provide a new approach to improve anode materials using carbon derived-from biomass with larger reversible capacity and long cycle life in LIBs.

Synthesis of a Yolk-Shell Nanostructured Silicon-Based Anode for High-Performance Li-Ion Batteries

Silicon is a desirable anode material for Li-ion batteries owing to its remarkable theoretical specific capacity of over 4000 mAh/g. Nevertheless, the poor cycling performance of pure Si electrodes caused by dramatic volume expansion has limited its practical application. To alleviate the adverse effects of Si expansion, we have synthesized anode materials of nano-Si particles trapped in a buffering space and outer carbon-based shells (Si@Void@C). The volume ratio of Si nanoparticle to void space could be adjusted accurately to approximately 1:3, which maintained the structural integrity of the as-designed nanoarchitecture during lithiation/delithiation and achieved a notable specific capacity of ~750 mAh/g for as-prepared half-cells. The yolk-shell nanostructure alleviates volumetric expansion on both material and electrode levels, which enhances the rate performance and cycling stability of the silicon-based anode.

A Multifunctional Interlocked Binder with Synergistic In Situ Covalent and Hydrogen Bonding for High-Performance Si Anode in Li-ion Batteries.

Silicon has garnered significant attention as a promising anode material for high-energy density Li-ion batteries. However, Si can be easily pulverized during cycling, which results in the loss of electrical contact and ultimately shortens battery lifetime. Therefore, the Si anode binder is developed to dissipate the enormous mechanical stress of the Si anode with enhanced mechanical properties. However, the interfacial stability between the Si anode binder and Cu current collector should also be improved. Here, a multifunctional thiourea polymer network (TUPN) is proposed as the Si anode binder. The TUPN binder provides the structural integrity of the Si anode with excellent tensile strength and resilience due to the epoxy-amine and silanol-epoxy covalent cross-linking, while exhibiting high extensibility from the random coil chains with the hydrogen bonds of thiourea, oligoether, and isocyanurate moieties. Furthermore, the robust TUPN binder enhances the interfacial stability between the Si anode and current collector by forming a physical interaction. Finally, the facilitated Li-ion transport and improved electrolyte wettability are realized due to the polar oligoether, thiourea, and isocyanurate moieties, respectively. The concept of this work is to highlight providing directions for the design of polymer binders for next-generation batteries.

Carbon coating optimization on porous silicon as high-performance anode material via fluidized bed chemical vapor deposition

The carbon layer coating is a promising solution to volume expansion and low electron conductivity in silicon-based anodes during lithiation. While numerous methods exist to generate these carbon coatings, Fluidized Bed Chemical Vapor Deposition (FBCVD) has proven superior due to its capacity for producing remarkably uniform and consistent carbon layers, primarily as a result of efficient mass and heat transfer characteristics. However, its application in the context of lithium-ion battery anodes has been sparsely explored and has been principally limited to silicon oxide as the base material. In this paper, porous silicon (PSi) obtained through acid etching of AlSi alloy with an average particle size of 300 mesh was taken as raw materials, and a fluidized bed reactor was employed to realize a uniform and tightly packed carbon layer. Relatively speaking, the PSi@C30 in this work offers a simpler process and promising electrochemical performance, opening a new door for the preparation of high-performance silicon-carbon anodes by FBCVD. Besides, PSi and high-quality carbon layers with structural advantages enabled the authors to obtain high-performance silicon-carbon anode materials. The resulting PSi@C30 composite demonstrated excellent initial coulomb efficiency (88.8 %) and cycling stability (with 83 % capacity retention after 100 cycles at 0.5 A g-1 and a reversible capacity of 1408 mAh g-1). Such a cost-effective and user-friendly technique facilitates the application of FBCVD in silicon-based anode materials for Li-ion batteries, thus accelerating the industrialization of silicon-carbon anodes for high-performance Li-ion batteries in the future.

Free-standing N-doped hollow carbon fiber encapsulate P/GeP hybrid anode for rechargeable Li-ion battery

Red phosphorus (RP) with appropriate working voltage and high lithium storage specific capacity has been considered as high-performance anode for Li-ion battery (LiB). However, the volume expansion of the RP anode reached 350 % during the intercalation/deintercalation of Li-ion processes, resulting in the detachment of active material and poor specific capacity. Herein, flexible hollow nanochannel carbon nanofiber was prepared through simple electrospinning, then P/GeP nano powder were encapsulated in the N-rich carbon nanofiber using a facile in situ synthesis method, where the introduction of GeP not only innovatively served as the high conductive dispersant for P, but simultaneously acted as the active component in reacting with Li-ion. The unique designed nanoarchitecture not only boosted the structural stability and electronic conductivity of the hybrid composite, but also facilitated the transport of electrons and Li-ion. Upon served as free-standing LiB anode, the N-doped hollow carbon fiber encapsulate P/GeP (P/GeP/C) anode displayed remarkably reversible capacities, superior rate performances, and long-term cycle stability for lithium storage. For instance, P/GeP/C of only 10.6 wt% GeP and 28.5 wt% P delivered 290.2 mA h g−1 under a high current density of 5 A g−1 and showed a high capacity of 575.6 and 436.9 mA h g−1 at a current density of 0.1 A g−1 and 1.0 A g−1 after 50 cycles, respectively.