锂硫电池由于能量密度高达2500 Wh/kg (电池级能量密度500Wh/kg）而得到研究者的广泛关注，成为最有潜力的新一代储能电池之一。然而，其充放电过程中多硫化物溶解、活性物质（S和Li2S/Li2S2）导电率低等问题严重影响了该体系的实际应用。针对上述问题，本项目将开展新型“双活性”锂硫电池机理研究并发展仿生学“树状-蜂巢”电极结构设计工作。一方面，设计并选用高比容量、充放电体积膨胀率低、无可溶性多硫化物生成的矾基硫化物VS4与硫元素共同作为活性物质实现“双活性”锂硫电池，并对不同荷电态下VS4与多硫化物之间的相互作用，VS4对多硫化物的催化氧化作用等机理进行深入研究；另一方面，通过发挥“树状”结构快速的物质运输和交换，蜂巢结构的大面积反应界面，以及结构稳固性，实现新型锂硫电极结构设计。最终，本项目将有望实现高负载（6mg/cm2）、高比例活性物质（≥80%）的新型锂硫电池。

Although lithium sulfur batteries are well known as one of the most promising candidates of the next generation batteries due to their high theoretical capacity of 2500 Wh/kg (over 500Wh/kg at battery level), their applications are greatly hindered by some shortcomings such as the dissolution of polysulfide during charge/discharge, and the poor conductivity of the active materials (S and Li2S/Li2S2). This project aims at developing novel "co-active material" system and theory for lithium sulfur batteries with the bio-mimic "tree-honeycomb" electrode structure design with 3D graphene. On the one hand, the VS4 is introduced as the co-active material for the novel system due to its high theoretical capacity, low volume expansion, and no dissolvable reaction product during cycling. Detailed theoretical study will be performed on the interaction between VS4 and the polysulfide at different charge/discharge state, as well as the catalyzing oxidation effect of VS4 towards polysulfide transformation. On the other hand, ultra-fast exchange and transportation capability is achieved via the "brunch" morphology channel in the electrode structure; while the large reaction interface and enhanced structure is obtained from the "honeycomb" structure of 3D graphene. In all, high loading (6mg/cm2) and high active material ratio (≥80%) lithium sulfur batteries with detailed theoretical study will be achieved in this project.