Scalable Solution Processing MoS2 Powders with Liquid Crystalline Graphene Oxide for Flexible Freestanding Films with High Areal Lithium Storage Capacity

Multiscale Structural Design of 2D Nanomaterials-based Flexible Electrodes for Wearable Energy Storage Applications

2D nanomaterials play a critical role in realizing high-performance flexible electrodes for wearable energy storge devices, owing to their merits of large surface area, high conductivity and high strength. The electrode is a complex system and the performance is determined by multiple and interrelated factors including the intrinsic properties of materials and the structures at different scales from macroscale to atomic scale. Multiscale design strategies have been developed to engineer the structures to exploit full potential and mitigate drawbacks of 2D materials. Analyzing the design strategies and understanding the working mechanisms are essential to facilitate the integration and harvest the synergistic effects. This review summarizes the multiscale design strategies from macroscale down to micro/nano-scale structures and atomic-scale structures for developing 2D nanomaterials-based flexible electrodes. It starts with brief introduction of 2D nanomaterials, followed by analysis of structural design strategies at different scales focusing on the elucidation of structure-property relationship, and ends with the presentation of challenges and future prospects. This review highlights the importance of integrating multiscale design strategies. Finding from this review may deepen the understanding of electrode performance and provide valuable guidelines for designing 2D nanomaterials-based flexible electrodes.

Optimized Pinecone-Squama-Structure MoS2-Coated CNT and Graphene Framework as Binder-Free Anode for Li-Ion Battery with High Capacity and Cycling Stability

Extensive research has been conducted on the development of high-rate and cyclic stability anodes for lithium batteries (LIBs) due to their high energy density. Molybdenum disulfide (MoS₂) with layered structure has garnered significant interest due to its exceptional theoretic Li⁺ storage behavior as anodes (670 mA h g^-1). However, achieving a high rate and long cyclic life of anode materials remains a challenge. Herein, we designed and synthesized a free-standing carbon nanotubes-graphene (CGF) foam, then presented a facile strategy to fabricate the MoS₂-coated CGF self-assembly anodes with different MoS₂ distributions. Such binder-free electrode possesses the advantages of both MoS₂ and graphene-based materials. Through rational regulation of the ratio of MoS₂, the MoS₂-coated CGF with uniformly distributed MoS₂ exhibits a nano pinecone-squama-like structure that can accommodate the large volume change during the cycle process, thereby significantly enhancing the cycling stability (417 mA h g^-1 after 1000 cycles), ideal rate performance, and high pseudocapacitive behavior (with a 76.6% contribution at 1 mV s^-1). Such a neat nano-pinecone structure can effectively coordinate MoS₂ and carbon framework, providing valuable insights for the construction of advanced anode materials.

N-doped graphene encapsulated MoS2nanosphere composite as a high-performance anode for lithium-ion batteries

MoS₂is widely used in lithium-ion batteries (LIBs) due to its high capacity (670 mAh g^-1) and unique two-dimensional structure. However, the further application was limited of MoS₂as anode materials suffer from its volume expansion and low conductivity. In this work, N-doped graphene encapsulated MoS₂nanosphere composite (MoS₂@NG) were prepared and its unique sandwich structure containing abundant mesopores and defects can efficiently enhance reaction kinetics. The MoS₂@NG electrode shows a reversible capacity of 975.9 mAh g^-1at 0.1 A g^-1after 100 cycles, and a reversible capacity of 325.2 mAh g^-1is still maintained after 300 cycles at 5 A g^-1. In addition, the MoS₂@NG electrode exhibites an excellent rate performance benefiting from the electrochemical properties dominated by capacitive behavior. This suggests that MoS₂@NG composite can be used as potential anode materials for LIBs.

Commercialization-Driven Electrodes Design for Lithium Batteries: Basic Guidance, Opportunities, and Perspectives

Current lithium-ion battery technology is approaching the theoretical energy density limitation, which is challenged by the increasing requirements of ever-growing energy storage market of electric vehicles, hybrid electric vehicles, and portable electronic devices. Although great progresses are made on tailoring the electrode materials from methodology to mechanism to meet the practical demands, sluggish mass transport, and charge transfer dynamics are the main bottlenecks when increasing the areal/volumetric loading multiple times to commercial level. Thus, this review presents the state-of-the-art developments on rational design of the commercialization-driven electrodes for lithium batteries. First, the basic guidance and challenges (such as electrode mechanical instability, sluggish charge diffusion, deteriorated performance, and safety concerns) on constructing the industry-required high mass loading electrodes toward commercialization are discussed. Second, the corresponding design strategies on cathode/anode electrode materials with high mass loading are proposed to overcome these challenges without compromising energy density and cycling durability, including electrode architecture, integrated configuration, interface engineering, mechanical compression, and Li metal protection. Finally, the future trends and perspectives on commercialization-driven electrodes are offered. These design principles and potential strategies are also promising to be applied in other energy storage and conversion systems, such as supercapacitors, and other metal-ion batteries.