A 3D and Stable Lithium Anode for High‐Performance Lithium–Iodine Batteries

Lithium metal is considered as the most promising anode material due to its high theoretical specific capacity and the low electrochemical reduction potential. However, severe dendrite problems have to be addressed for fabricating stable and rechargeable batteries (e.g., lithium–iodine batteries). To fabricate a high‐performance lithium–iodine (Li–I₂) battery, a 3D stable lithium metal anode is prepared by loading of molten lithium on carbon cloth doped with nitrogen and phosphorous. Experimental observations and theoretical calculation reveal that the N,P codoping greatly improves the lithiophilicity of the carbon cloth, which not only enables the uniform loading of molten lithium but also facilitates reversible lithium stripping and plating. Dendrites formation can thus be significantly suppressed at a 3D lithium electrode, leading to stable voltage profiles over 600 h at a current density of 3 mA cm^?2. A fuel cell with such an electrode and a lithium–iodine cathode shows impressive long‐term stability with a capacity retention of around 100% over 4000 cycles and enhanced high‐rate capability. These results demonstrate the promising applications of 3D stable lithium metal anodes in next‐generation rechargeable batteries.     

A Novel High‐Capacity Anode Material Derived from Aromatic Imides for Lithium‐Ion Batteries

A novel anode material for lithium‐ion batteries derived from aromatic imides with multicarbonyl group conjugated with aromatic core structure is reported, benzophenolne‐3,3′,4,4′‐tetracarboxylimide oligomer (BTO). It could deliver a reversible capacity of 829 mA h g^?1 at 42 mA g^?1 for 50 cycles with a stable discharge plateaus ranging from 0.05–0.19 V versus Li⁺/Li. At higher rates of 420 and 840 mA g^?1, it can still exhibit excellent cycling stability with a capacity retention of 88% and 72% after 1000 cycles, delivering capacity of 559 and 224 mA h g^?1. In addition, a rational prediction of the maximum amount of lithium intercalation is proposed and explored its possible lithium storage mechanism.     

Rationally Designed Silicon Nanostructures as Anode Material for Lithium‐Ion Batteries

Silicon (Si) is promising for high capacity anodes in lithium‐ion batteries due to its high theoretical capacity, low working potential, and natural abundance. However, there are two main drawbacks that impede its further practical applications. One is the huge volume expansion generating during lithiation and delithiation progresses, which leads to severe structural pulverization and subsequently rapid capacity fading of the electrode. The other is the relatively low intrinsic electronic conductivity, therefore, seriously impacting the rate performance. In the past decades, numerous efforts have been devoted for improving the cycling stability and rate capability by rational designs of different nanostructures of Si materials and incorporations with some conductive agents. In this review, the authors summarize the exciting recent research works and focus on not only the synthesis techniques, but also the composition strategies of silicon nanostructures. The advantages and disadvantages of the nanostructures as well as the perspective of this research field are also discussed. We aim to give some reference for engineering application on Si anodes in lithium ion batteries.     

Intercalating Ti2Nb14O39 Anode Materials for Fast‐Charging,High‐Capacity and Safe Lithium–Ion Batteries

Ti–Nb–O binary oxide materials represent a family of promising intercalating anode materials for lithium‐ion batteries. In additional to their excellent capacities (388–402 mAh g^–1), these materials show excellent safety characteristics, such as an operating potential above the lithium plating voltage and minimal volume change. Herein, this study reports a new member in the Ti–Nb–O family, Ti₂Nb₁₄O₃₉, as an advanced anode material. Ti₂Nb₁₄O₃₉ porous spheres (Ti₂Nb₁₄O₃₉‐S) exhibit a defective shear ReO₃ crystal structure with a large unit cell volume and a large amount of cation vacancies (0.85% vs all cation sites). These morphological and structural characteristics allow for short electron/Li⁺‐ion transport length and fast Li⁺‐ion diffusivity. Consequently, the Ti₂Nb₁₄O₃₉‐S material delivers significant pseudocapacitive behavior and excellent electrochemical performances, including high reversible capacity (326 mAh g^?1 at 0.1 C), high first‐cycle Coulombic efficiency (87.5%), safe working potential (1.67 V vs Li/Li⁺), outstanding rate capability (223 mAh g^–1 at 40 C) and durable cycling stability (only 0.032% capacity loss per cycle over 200 cycles at 10 C). These impressive results clearly demonstrate that Ti₂Nb₁₄O₃₉‐S can be a promising anode material for fast‐charging, high capacity, safe and stable lithium‐ion batteries.     

Scalable 2D Mesoporous Silicon Nanosheets for High‐Performance Lithium‐Ion Battery Anode

Constructing unique mesoporous 2D Si nanostructures to shorten the lithium‐ion diffusion pathway, facilitate interfacial charge transfer, and enlarge the electrode–electrolyte interface offers exciting opportunities in future high‐performance lithium‐ion batteries. However, simultaneous realization of 2D and mesoporous structures for Si material is quite difficult due to its non‐van der Waals structure. Here, the coexistence of both mesoporous and 2D ultrathin nanosheets in the Si anodes and considerably high surface area (381.6 m² g^?1) are successfully achieved by a scalable and cost‐efficient method. After being encapsulated with the homogeneous carbon layer, the Si/C nanocomposite anodes achieve outstanding reversible capacity, high cycle stability, and excellent rate capability. In particular, the reversible capacity reaches 1072.2 mA h g^?1 at 4 A g^?1 even after 500 cycles. The obvious enhancements can be attributed to the synergistic effect between the unique 2D mesoporous nanostructure and carbon capsulation. Furthermore, full‐cell evaluations indicate that the unique Si/C nanostructures have a great potential in the next‐generation lithium‐ion battery. These findings not only greatly improve the electrochemical performances of Si anode, but also shine some light on designing the unique nanomaterials for various energy devices.     

Anode Interface Engineering and Architecture Design for High‐Performance Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries are considered as one of the most promising options to realize rechargeable batteries with high energy capacity. Previously, research has mainly focused on solving the polysulfides' shuttle, cathode volume changes, and sulfur conductivity problems. However, the instability of anodes in Li–S batteries has become a bottleneck to achieving high performance. Herein, the main efforts to develop highly stable anodes for Li–S batteries, mainly including lithium metal anodes, carbon‐based anodes, and alloy‐based anodes, are considered. Based on these anodes, their interfacial engineering and structure design are identified as the two most important directions to achieve ideal anodes. Because of high reactivity and large volume change during cycling, Li anodes suffer from severe side reactions and structure collapse. The solid electrolyte interphase formed in situ by modified electrolytes and ex situ artificial coating layers can enhance the interfacial stability of anodes. Replacing common Li foil with rationally designed anodes not only suppresses the formation of dendritic Li but also delays the failure of Li anodes. Manipulating the anode interface engineering and rationally designing anode architecture represents an attractive path to develop high‐performance Li–S batteries.     

Oxygen‐Deficient Ferric Oxide as an Electrochemical Cathode Catalyst for High‐Energy Lithium–Sulfur Batteries

Lithium–sulfur batteries, as one of promising next‐generation energy storage devices, hold great potential to meet the demands of electric vehicles and grids due to their high specific energy. However, the sluggish kinetics and the inevitable “shuttle effect” severely limit the practical application of this technology. Recently, design of composite cathode with effective catalysts has been reported as an essential way to overcome these issues. In this work, oxygen‐deficient ferric oxide (Fe₂O_3?x), prepared by lithiothermic reduction, is used as a low‐cost and effective cathodic catalyst. By introducing a small amount of Fe₂O_3?x into the cathode, the battery can deliver a high capacity of 512 mAh g^?1 over 500 cycles at 4 C, with a capacity fade rate of 0.049% per cycle. In addition, a self‐supporting porous S@KB/Fe₂O_3?x cathode with a high sulfur loading of 12.73 mg cm^?2 is prepared by freeze‐drying, which can achieve a high areal capacity of 12.24 mAh cm^?2 at 0.05 C. Both the calculative and experimental results demonstrate that the Fe₂O_3?x has a strong adsorption toward soluble polysulfides and can accelerate their subsequent conversion to insoluble products. As a result, this work provides a low‐cost and effective catalyst candidate for the practical application of lithium–sulfur batteries.     

Nanospace‐Confinement Synthesis: Designing High‐Energy Anode Materials toward Ultrastable Lithium‐Ion Batteries

Exploiting high‐capacity and durable electrode materials is pivotal to developing lithium‐ion batteries (LIBs) and their applications. Multiscaled nanomaterials have been demonstrated to efficiently couple the advantages of each component on different scales in energy storage fields. However, the precise control of the microstructure remains a great challenge for maximizing their contributions. Nanospace‐confined synthesis provides a proactive strategy to build novel multiscaled nanomaterials with controllable internal void space for circumventing the intrinsic volume effects in the charge/discharge process. Herein, the rational design and synthesis of multiscaled high‐capacity anode materials are mainly summarized according to their electrochemical mechanisms by choosing 1D channel, 2D interlayer, and 3D space as representative confinement reaction environments. The structure–performance relationships are clarified with the assistance of quantitative calculations, molecular simulations, and so forth. Finally, future potentials and challenges of such a synthesis tactic in designing high‐performance electrode materials for next‐generation secondary batteries are outlooked.     

Strategies toward High‐Performance Cathode Materials for Lithium–Oxygen Batteries

Rechargeable aprotic lithium (Li)–O₂ batteries with high theoretical energy densities are regarded as promising next‐generation energy storage devices and have attracted considerable interest recently. However, these batteries still suffer from many critical issues, such as low capacity, poor cycle life, and low round‐trip efficiency, rendering the practical application of these batteries rather sluggish. Cathode catalysts with high oxygen reduction reaction (ORR) and evolution reaction activities are of particular importance for addressing these issues and consequently promoting the application of Li–O₂ batteries. Thus, the rational design and preparation of the catalysts with high ORR activity, good electronic conductivity, and decent chemical/electrochemical stability are still challenging. In this Review, the strategies are outlined including the rational selection of catalytic species, the introduction of a 3D porous structure, the formation of functional composites, and the heteroatom doping which succeeded in the design of high‐performance cathode catalysts for stable Li–O₂ batteries. Perspectives on enhancing the overall electrochemical performance of Li–O₂ batteries based on the optimization of the properties and reliability of each part of the battery are also made. This Review sheds some new light on the design of highly active cathode catalysts and the development of high‐performance lithium–O₂ batteries.     

Preparation of MoS2‐Coated Three‐Dimensional Graphene Networks for High‐Performance Anode Material in Lithium‐Ion Batteries

A novel composite, MoS₂‐coated three‐dimensional graphene network (3DGN), referred to as MoS₂/3DGN, is synthesized by a facile CVD method. The 3DGN, composed of interconnected graphene sheets, not only serves as template for the deposition of MoS₂, but also provides good electrical contact between the current collector and deposited MoS₂. As a proof of concept, the MoS₂/3DGN composite, used as an anode material for lithium‐ion batteries, shows excellent electrochemical performance, which exhibits reversible capacities of 877 and 665 mAh g^?1 during the 50^th cycle at current densities of 100 and 500 mA g^?1, respectively, indicating its good cycling performance. Furthermore, the MoS₂/3DGN composite also shows excellent high‐current‐density performance, e.g., depicts a 10^th‐cycle capacity of 466 mAh g^?1 at a high current density of 4 A g^?1.     

An Amorphous/Crystalline Incorporated Si/SiOx Anode Material Derived from Biomass Corn Leaves for Lithium‐Ion Batteries

The fabrication of silicon (Si) anode materials derived from high silica‐containing plants enables effective utilization of subsidiary agricultural products. However, the electrochemical performances of synthesized Si materials still require improvement and thus need further structural design and morphology modifications, which inevitably increase preparation time and economic cost. Here, the conversion of corn leaves into Si anode materials is reported via a simple aluminothermic reduction reaction without other modifications. The obtained Si material inherits the structural characteristics of the natural corn leaf template and has many inherent advantages, such as high porosity, amorphous/crystalline mixture structure, and high‐valence SiO_x residuals, which significantly enhance the material's structural stability and electrode adhesive strength, resulting in superior electrochemical performances. Rate capability tests show that the material delivers a high capacity of 1200 mA h g^?1 at 8 A g^?1 current density. After 300 cycles at 0.5 A g^?1, the material maintains a high specific capacity of 2100 mA h g^?1, with nearly 100% capacity retention during long‐term cycling. This study provides an economical route for the industrial production of Si anode materials for Lithium‐Ion batteries.     

Carbon‐Coated Li3VO4 Spheres as Constituents of an Advanced Anode Material for High‐Rate Long‐Life Lithium‐Ion Batteries

Lithium‐ion batteries are receiving considerable attention for large‐scale energy‐storage systems. However, to date the current cathode/anode system cannot satisfy safety, cost, and performance requirements for such applications. Here, a lithium‐ion full battery based on the combination of a Li₃VO₄ anode with a LiNi_0.5Mn_1.5O₄ cathode is reported, which displays a better performance than existing systems. Carbon‐coated Li₃VO₄ spheres comprising nanoscale carbon‐coating primary particles are synthesized by a morphology‐inheritance route. The observed high capacity combined with excellent sample stability and high rate capability of carbon‐coated Li₃VO₄ spheres is superior to other insertion anode materials. A high‐performance full lithium‐ion battery is fabricated by using the carbon‐coated Li₃VO₄ spheres as the anode and LiNi_0.5Mn_1.5O₄ spheres as the cathode; such a cell shows an estimated practical energy density of 205 W h kg^?1 with greatly improved properties such as pronounced long‐term cyclability, and rapid charge and discharge.