Anode For Lithium Storage Research Articles

CNTs and rGO synergistically enhance the cycling stability of yolk-shell silicon anodes for efficient lithium storage

Si-based anode materials have received a lot of attention from researchers due to their ultra-high theoretical specific capacity. However, poor conductivity and volume expansion during cycling have seriously hindered their further commercialization. To address the problems of Si-based materials, the multidimensional carbon materials constructed from Zeolitic imidazolate framework (ZIF) derived carbon and carbon nanotubes (CNTs) followed by the addition of reduced graphene oxide (rGO) are employed to encapsulate silicon nanoparticles (Si@C-ZIF@CNTs@rGO) to prepare a composite anode with a yolk-shell structure, which are prepared by mechanical stirring, electrostatic self-assembly and two-step calcination. The heat-treated ZIF materials not only form a unique yolk-shell structure that can effectively inhibit the volume expansion of silicon nanoparticles, but also derive rigid carbon shells and carbon nanotubes to improve the electrical conductivity of the anode materials, while rGO introduced by electrostatic self-assembly provides a large number of transport paths for electrons and ions. In a full battery test composed of LiFePO4 cathode, the composite cathode material loses only 2.4 % of its specific capacity after 100 cycles at 0.5 C current density. This work provides new ideas for multidimensional carbon structures to improve the lithium storage performance of silicon-based anodes.

Sn3O4 nanosheets with N-doped carbon coating for high performance lithium storage

Tin-based oxides are promising anode materials for lithium ion batteries (LIBs) in virtue of their many advantages including high capacity, abundant reserves and environmental friendliness. Yet, previous studies mainly focus on the SnO2-based anodes for lithium storage. Considering that the mixed valence and layered crystal structure of Sn3O4 may lead to better lithium storage properties, Sn3O4-based anode material is designed and synthesized through a facile hydrothermal method in this work. The as-prepared Sn3O4 nanosheets are coated with N-doped carbon layers (∼15 nm) on both sides through dopamine polymerization and subsequent polydopamine carbonization to solve the issues of poor intrinsic electronic conductivity and drastic volume change during LiSn alloying/dealloying, which have hindered their application in LIBs. With the structural and composition advantages brought by the thick N-doped carbon layers, the Sn3O4@NC nanosheets delivered a remarkable reversible capacity (1222 mAh g−1 after 50 cycles at 200 mA g−1) and excellent rate performance when applied in LIB as anode material, owing to the improved electrical conductivity and strengthened structure stabilities. Importantly, we demonstrate a convenient strategy to realize carbon coating in the fabrication of Sn3O4-based anode materials, which could inspire the development of other Sn3O4-based anode materials with excellent lithium storage properties.

A Bimetallic Ni–Fe MOF Nanofiber as High Performance Anode for Enhancing Lithium Storage

A Bimetallic Ni–Fe MOF Nanofiber as High Performance Anode for Enhancing Lithium Storage

Electrochemical reconstruction: a new perspective on Sn metal–organic complex microbelts as robust anode for lithium storage

Electrochemical reconstruction: a new perspective on Sn metal–organic complex microbelts as robust anode for lithium storage

GeO2 Nanoparticles Decorated in Amorphous Carbon Nanofiber Framework as Highly Reversible Lithium Storage Anode.

Germanium oxide (GeO2) is a high theoretical capacity electrode material due to its alloying and conversion reaction. However, the actual cycling capacity is rather poor on account of suffering low electron/ion conductivity, enormous volume change and agglomeration in the repeated lithiation/delithiation process, which renders quite a low reversible electrochemical lithium storage reaction. In this work, highly amorphous GeO2 particles are uniformly distributed in the carbon nanofiber framework, and the amorphous carbon nanofiber not only improves the conduction and buffers the volume changes but also prevents active material agglomeration. As a result, the present GeO2 and carbon composite electrode exhibits highly reversible alloying and conversion processes during the whole cycling process. The two reversible electrochemical reactions are verified by differential capacity curves and cyclic voltammetry measurements during the whole cycling process. The corresponding reversible capacity is 747 mAh g-1 after 300 cycles at a current density of 0.3 A g-1. The related reversible capacities are 933, 672, 487 and 302 mAh g-1 at current densities of 0.2, 0.4, 0.8 and 1.6 A g-1, respectively. The simple strategy for the design of amorphous GeO2/carbon composites enables potential application for high-performance LIBs.

Design and Construction of Carbon-Coated Fe3 O4 /Cr2 O3 Heterostructures Nanoparticles as High-Performance Anodes for Lithium Storage.

Transition metal oxides, highly motivated anodes for lithium-ion batteries due to high theoretical capacity, typically afflict by inferior conductivity and significant volume variation. Architecting heterogeneous structures with distinctive interfacial features can effectively regulate the electronic structure to favor electrochemical properties. Herein, an engineered carbon-coated nanosized Fe3 O4 /Cr2 O3 heterostructure with multiple interfaces is synthesized by a facile sol-gel method and subsequent heat treatment. Such ingenious components and structural design deliver rapid Li+ migration and facilitate charge transfer at the heterogeneous interface. Simultaneously, the strong coupling synergistic interactions between Fe3 O4 , Cr2 O3 , and carbon layers establish multiple interface structures and built-in electric fields, which accelerate ion/electron transport and effectively eliminate volume expansion. As a result, the multi-interface heterostructure, as a lithium-ion battery anode, exhibits superior cycling stability maintaining a reversible capacity of 651.2 mAh g-1 for 600 cycles at 2 C. The density functionaltheorycalculations not only unravel the electronic structure of the modulation but also illustrate favorable lithium-ion adsorption kinetics. This multi-interface heterostructure strategy offers a pathway for the development of advanced alkali metal-ion batteries.

Rational CoP/C complex film as high-reliable anode for lithium storage, from polyols regulated growth of graphene-like Co alkoxide

Rational cobalt phosphide/carbon (CoP/C) complex film composed of densely assembled CoP-in-carbon nanosheets was successfully constructed via filtration-induced self-assembly and in-situ transformation strategy. The successful implementation of this method relies on the morphology controlled preparation of graphene-like Co alkoxide by varying the chain length of polyols to regulate the polycondensation process. The graphene-like CoP-in-carbon construction units can accelerate ions/electrons transportation and guarantee structural robustness. Thanks to its ideal composite structure, CoP/C complex film exhibits outstanding cycling and rate performances, including high capacities up to 920.5 mAh g−1 over 200 cycles at 1 A g−1 and 826.5/662.3 mAh g−1 after cycling under 2/4 A g−1 over 1000 cycles. Besides, full-cells constructed with CoP/C complex film anodes and LiCoO2 cathodes exhibit superior cycling stability and reliable capacities of 773.4/518.7 mAh g−1 after 200 cycles at high rates of 1/4 A g−1. Such efficient and reliable strategy can offer new insights and understanding about the construction of advanced film materials for energy-storage devices.

Gallic Acid Resin as an Efficient Lithium Storage Anode Material for 3.6 V Li-Ion Batteries

Gallic Acid Resin as an Efficient Lithium Storage Anode Material for 3.6 V Li-Ion Batteries

Homogeneous Intercalation Chemistry and Ultralow Strain of 1T’’’ MoS2 for Stable Potassium Storage

AbstractIntercalation anodes usually exhibit better cyclability than conversion and alloying anodes for lithium or sodium storage due to the robust layered structure. However, for larger‐sized potassium accommodation, these intercalation anodes usually undergo huge layer expansion and structural distortion, triggering severe capacity fading. Herein, the novel 1T’’’ MoS2 is revealed the intercalation anode for stable K+ storage, in which metallic Mo─Mo bonds and puckered S layers accelerate the charge transfer and homogeneous K+ insertion. Moreover, the ultralow strain (3.5%) induced by the non‐detachable potassium ions pillar sustains the layered structure. Consequently, 1T’’’ MoS2 achieves a reversible capacity of 125 mA h g−1 at 0.2 C and keeps nearly 100% capacity retention at 1 C over 500 cycles. In situ characterizations and density functional theory simulations reveal the in‐depth intercalation reaction accompanied by the MoS2 phase transformation between 1T’’’ and 1T’ during cycling. Furthermore, a 1T’’’ MoS2//MCMB K‐dual ion battery displays a superior cycling lifespan with 98% capacity retention over 250 cycles. This study provides a new intercalation anode and contribute to the electrode design for stable potassium ion storage.

Strategies to improve metal-organic frameworks and their derived oxides as lithium storage anode materials

Lithium-ion batteries (LIBs) are widely used as energy storage technology in emerging markets such as electric vehicles. The development of anode materials that can replace graphite materials is a hotspot of current research. Metal-organic frameworks (MOFs), as a kind of important porous inorganic organic hybrid crystals, have been developed and used as anode materials for LIBs. MOFs can be used as precursors for transition metal oxides (TMOs) with nanostructures based on unique properties such as their unique structure and morphological characteristic, and controllable skeleton composition. In this review, the application and recent progress of MOFs and their derived TMOs in anode materials for LIBs are reviewed. Attention is also paid to their electrochemical mechanisms and the mechanism of the cyclic capacity enhancement phenomenon. Finally, the challenges of MOFs and their derived TMOs as LIBs anode materials are discussed, and modification strategies to improve their electrochemical performance are analyzed and summarized.

Construction of oxygen vacancy-rich ZnO@carbon nanofiber aerogels as a free-standing anode for superior lithium storage

The development of next-generation high-capacity freestanding materials as electrodes in lithium-ion batteries (LIBs) has significant potential. Here, oxygen vacancy-rich ZnO (Ov-ZnO) deposited on carbonized bacterial cellulose (CBC) aerogels is developed via in-situ uniformly growing ZIF-8-NH2 particles on CBC aerogels, followed by the hydrazine reduction and pyrolysis. The CBC serves as a free-standing skeleton to disperse and support ZIF-8-NH2 derived ZnO while the introduction of oxygen vacancies can effectively promote the internal ion/electron transfer. As a result, the obtained free-standing aerogels (Ov-ZnO@CBC) displays a reversible capacity of 710 mAh g−1 at 1 A g−1 after 1000 cycles, which is superior to ZnO@CBC without hydrazine reduction treatment. Furthermore, the assembled Li free-standing full cell using the Ov-ZnO@CBC composite as the anode and BC@LiFePO4 (BC@LFP) as the cathode exhibits an outstanding cycling performance of 150 mAh g−1 after 100 cycles at 0.1 A g−1, displaying satisfactory lithium-ion storage capability. It is noteworthy that both Ov-ZnO@CBC and BC@LFP are obtained in the form of a free-standing aerogel. This work offers a strategy to prepare high-capacity and long-cycle self-supporting aerogel-based electrodes for flexible LIBs.

Porous carbon derived from cherry blossom leaves treatment with Fe3O4 enhanced the electrochemical performance of a lithium storage anode

Metal oxides have been proposed as promising anode materials for next-generation batteries, but the large volume changes and poor electron and ion conductivity limit their electrochemical performance. To mitigate the negative effects of volume expansion on battery performance, a flower-like Fe3O4 structure coated with carbon is studied via one step wet chemical method. The Fe3O4 particles are uniformly distributed in highly porous carbon derived from cherry blossom leaves, resulting in a larger specific area and higher conductivity for the Fe3O4@C anode. In this hybrid Fe3O4@C nanocomposite, the ultrafine carbon coating effectively reduces volume expansion while providing excellent electrochemical performance. The flower-like Fe3O4@C electrodes demonstrate a specific capacity of approximately 1110 mAh g–1 at a current density of 1.0 A g–1. Moreover, the composite material Fe3O4@C exhibits a specific capacity of 848.1 mAh g–1 at a high current density of 2.0 A g–1 over 1000 cycles. These results indicate that the hybrid composition Fe3O4@C possesses excellent electrochemical properties, and suggest that this strategy could be applied to other hybrid materials for energy harvesting and storage.

Enhanced Interfacial Magnetization is Responsible for the Negative Capacity Fading of Cobalt Ditelluride Anodes for Lithium Storage.

In lithium-ion batteries (LIBs), the stabilized capacities of transition metal compound anodes usually exhibit higher values than their theoretical values due to the interfacial charge storage, the formation of reversible electrolyte-derived surface layer, or interfacial magnetization. But the effectively utilizing the mechanisms to achieve novel anodes is rarely explored. Herein, a novel nanosized cobalt ditelluride (CoTe2 ) anodes with ultra-high capacity and long term stability is reported. Electrochemical tests show that the lithium storage capacity of the best sample reaches 1194.7mA h g-1 after 150 cycles at 0.12 A g-1 , which increases by 57.8% compared to that after 20 cycles. In addition, the sample offers capacities of 546.6 and 492.1mA h g-1 at 0.6 and 1.8 A g-1 , respectively. During cycles, CoTe2 particles (average size 20nm) are gradually pulverized into the smaller nanoparticles (<3nm), making the magnetization more fully due to the larger contact area of Co/Li2 Te interface, yielding an increased capacity. The negative capacity fading is observed, and verified by ex situ structural characterizations and in situ electrochemical measurements. The proposed strategy can be further extended to obtain other high-performance ferromagnetic metal based electrodes for energy storage applications.

Vesicular mesoporous copper oxide as anode for high lithium storage

Vesicular mesoporous copper oxide as anode for high lithium storage

Binder- and conductive additive-free Ga2O3 nanowires as a self-healing anode for lithium storage

High-capacity anode materials have stimulated much attention to developing high-performance lithium-ion batteries. However, high-capacity anode materials commonly suffer from the pulverization matter that greatly hinders their practical applications, especially in terms of the high proportion of active materials. In this work, a Ga2O3 nanowire electrode is synthesized by thermal evaporation and immediately used as an anode without the aid of binders and conductive additives. The 3D interconnected architecture of the Ga2O3 nanowire electrode shortens lithium diffusion lengths and expedites reaction kinetics. The Ga2O3 nanowires exhibit high elasticity and a self-healing ability which is inherited from metallic Ga formed during the electrochemical transition process, thus circumventing the formidable pulverization issue to a certain extent. Benefiting from the unique structural, mechanical, and chemical attributes, the as-grown Ga2O3 nanowire electrode gives a high initial lithiation capacity of 1462 mAh g−1 under a current density of 0.1 ​A ​g−1. It delivers good cyclic stability with a reversible capacity of 445 mAh g−1 after 200 cycles at 0.5 ​A ​g−1. Furthermore, the investigation of lithium storage behaviors indicates the high rate capability of Ga2O3 nanowires. This paper contributes to understanding binder- and conductive additive-free electrodes consisting of high-capacity active materials from various viewpoints.

Reversible conversion–alloying of cobalt–bismuth oxide nanoneedles for long-life lithium storage anodes

Materials that undergo combined conversion and alloying reactions are promising as anodes for lithium storage application because they can accommodate multiple lithium ions. However, irreversible conversion reactions, large voltage hysteresis, poor rate capabilities, and low initial Coulombic efficiencies during continuous discharge–charge cycling make practical applications of conversion–alloying materials challenging. Herein, we present cobalt–bismuth oxide (CBO) nanoneedles, a new bimetallic material in which Li+-ion uptake proceeds stepwise, thus effectively suppressing volume expansion. During the initial lithiation stage, the CBO nanoneedles undergo a conversion reaction to form nanodomains of low-oxidation-state Coδ+ (δ ≤ 2) in a Li2O matrix. At the next potential platform, the Bi phase attracts Li+ ions via an alloying reaction, while the Coδ+/Li2O phase hinders excessive volume expansion. Consequently, the CBO electrode delivers a high reversible discharge capacity of 392 mAh g−1 at 50 mA g−1 for up to 100 cycles. Further, an ultrastable long-term capacity of 300 mAh g−1 at 250 mA g−1 is realized over 1000 cycles. The stepwise lithiation process decreases volume expansion significantly (by ∼10%), which leads to good cyclability. Owing to their ease of preparation and excellent performance characteristics, CBO nanoneedles are an attractive long-life anode material for lithium-ion batteries.

Precise Construction of Sn/C Composite Membrane with Graphene-Like Sn-in-Carbon Structural Units toward Hyperstable Anode for Lithium Storage.

A new-type binder-free Sn/C composite membrane with densely stacked Sn-in-carbon nanosheets was prepared by vacuum-induced self-assembly of graphene-like Sn alkoxide and following in situ thermal conversion. The successful implementation of this rational strategy is based on the controllable synthesis of graphene-like Sn alkoxide by using Na-citrate with the critical inhibitory effect on polycondensation of Sn alkoxide along the a and b directions. Density functional theory calculations reveal that graphene-like Sn alkoxide can be formed under the joint action of oriented densification along the c axis and continuous growth along the a and b directions. The Sn/C composite membrane constructed by graphene-like Sn-in-carbon nanosheets can effectively buffer volume fluctuation of inlaid Sn during cycling and much enhance the kinetics of Li+ diffusion and charge transfer with the developed ion/electron transmission paths. After temperature-controlled structure optimization, Sn/C composite membrane displays extraordinary Li storage behaviors, including reversible half-cell capacities up to 972.5 mAh g-1 at a density of 1 A g-1 for 200 cycles, 885.5/729.3 mAh g-1 over 1000 cycles at large current densities of 2/4 A g-1, and terrific practicability with reliable full-cell capacities of 789.9/582.9 mAh g-1 up to 200 cycles under 1/4 A g-1. It is worthy of noting that this strategy may open up new opportunities to fabricate advanced membrane materials and construct hyperstable self-supporting anodes in lithium ion batteries.

Biomass Alginate Derived Oxygen-Enriched Carbonaceous Materials with Partially Graphitic Nanolayers for High Performance Anodes in Lithium-Ion Batteries

Lithium-ion batteries with high reversible capacity, high-rate capability, and extended cycle life are vital for future consumer electronics and renewable energy storage. There is a great deal of interest in developing novel types of carbonaceous materials to boost lithium storage properties due to the inadequate properties of conventional graphite anodes. In this study, we describe a facile and low-cost approach for the synthesis of oxygen-doped hierarchically porous carbons with partially graphitic nanolayers (Alg-C) from pyrolyzed Na-alginate biopolymers without resorting to any kind of activation step. The obtained Alg-C samples were analyzed using various techniques, such as X-ray diffraction, Raman, X-ray photoelectron spectroscopy, scanning electron microscope, and transmission electron microscope, to determine their structure and morphology. When serving as lithium storage anodes, the as-prepared Alg-C electrodes have outstanding electrochemical features, such as a high-rate capability (120 mAh g-1 at 3000 mA g-1) and extended cycling lifetimes over 5000 cycles. The post-cycle morphologies ultimately provide evidence of the distinct structural characteristics of the Alg-C electrodes. These preliminary findings suggest that alginate-derived carbonaceous materials may have intensive potential for next-generation energy storage and other related applications.

In situ anchoring of MnO nanoparticles into three-dimensional nitrogen-doped porous carbon framework as a stable anode for high-performance lithium storage

Although transition metal oxides have the advantages of large theoretical capacity, low cost and eco-friendliness, their application as anodes for lithium-ion batteries (LIBs) is still limited due to their undesirable electrical conductivity and large volume expansion. Herein, a novel two-step rapid freeze-drying-calcination strategy was applied to prepare highly dispersed nano-MnO-anchored three-dimensional nitrogen-doped porous carbon framework composites (MnO@3D N-PCF). Compared with MnO and undoped MnO@3D PCF, the MnO@3D N-PCF anode exhibits superb cycle stability, remarkable specific capacity and impressive high-rate performance (1037.0 mAh g−1 over 100 cycles at 0.1 A g−1 and 760.9 mAh g−1 over 500 cycles at 5 A g−1), mainly due to its well-designed 3D nanoarchitecture. It is found that 3D nitrogen-doped carbon networks can act as stable conductive bridges to facilitate electron transport and sufficient diffusion channels for Li ions. The MnO nanoparticles obtained by rapid lyophilization and calcination technology are highly dispersed in the porous 3D carbon skeleton, which can buffer volume expansion and preserve the stability of the electrode. It is expected that this simple and green synthesis strategy will open the door for the development of transition metal oxide/carbon three-dimensional nanocomposites with high stability and excellent electrochemical properties.

MoS2/SnS2 synergistically cooperate with graphene to construct high-quality lithium storage anode materials

The specific capacity of MoS2 is much larger than that of commercial graphite, but it cannot be practically applied due to its poor electrical conductivity and low cycle stability. Although the conductivity of the material can be greatly increased after compounding with graphene, MoS2 will be unevenly distributed on graphene and form agglomeration because of the charge incompatibility caused by negatively charged molybdenum sources of GO and MoS2. Therefore, the capacity of the as-prepared MoS2/graphene material is extremely unstable and decays to a great extent during cycling. In this paper, a three-dimensional layered structure of MoS2/SnS2 and graphene (MoS2/SnS2-GS) as anode material for sulfur-doped lithium-ion batteries were prepared by a one-pot hydrothermal method. Sn4+ is a bridge connecting two anionic materials, neutralizes negatively charged GO through electrostatic interaction, and adsorbs MoO42-. Furthermore, the heterostructure of MoS2/SnS2 provides a faster and more efficient channel for Li+. Moreover, graphene with high surface area and excellent electrical conductivity allow the electrolyte to provide much fuller access to enter materials, which promotes the transport of Li+. Sulfur doping has a strong effect on surface activation, resulting in a significant increase in surface adsorption and chemical kinetics. Consequently, MoS2/SnS2-GS exhibits excellent capacity and cycling performance as anode material for Lithium-ion batteries (LIBs), maintaining a specific capacity of 2007.4 mAh g−1 at 0.1 A g−1 (100 cycles), and 3224.3 mAh g−1 at 0.5 A g−1 (600 cycles). The preparation method of MoS2/SnS2-GS material provides a great reference for the development of anode materials for disulfide LIBs.