用于无金属锂锂硫电池的高性能纳米硫化锂/碳复合正极材料研究

Lithium-secondary batteries have been recognized as one of the most powerful techniques for the storage of clean energy. The development of lithium secondary batteries with high performance but environmental benignity is essential to strengthen the electric vehicle (EV) industry in China. The performance of lithium-secondary batteries is heavily relied on the electrode materials. Specifically, the conventional intercalation-type cathode materials with limited theoretical capacities have been the bottle-neck issue for enhancing the specific energy of lithium-secondary batteries. Among available lithium-secondary batteries, lithium-sulfur batteries based on high-capacity sulfur cathode and metallic lithium anode have attracted extensive interests because of its very high energy density. One of the critical obstacles for its practical use is the potentially safety hazards (e.g., fire and explosion) caused by using metallic lithium anode in flammable organic electrolyte. In this project, we will devote to develop the new strategy for elegant design and controllable fabrication of high-performance but low-cost Li2S/carbon nanocomposites with novel structure. The mechanism involved in the material fabrication, nanostructure engineering, property tuning and electrochemical applications will be synergistically understood in multiple scale and dimensions. Finally, the high-performance Li2S/C cathode materials will be exploited for the construction of metallic-lithium-free lithium-sulfur batteries with high specific energy density but high safety by coupling with high-capacity anode materials, which offers a new research line to cross the obstacle in practical implementation of lithium-sulfur batteries.

锂二次电池是当前综合性能最好的储能与动力电池技术之一，发展高能量、长寿命、绿色环保的锂二次电池是我国发展新能源汽车产业、解决能源与环境可持续发展问题的重大战略需求。电极材料是锂二次电池的核心储能组件，传统正极材料理论容量有限，是制约锂二次电池能量密度提高的瓶颈。基于高比容量硫正极与金属锂负极的锂硫电池是近年来备受瞩目的新型锂二次电池技术，但因使用金属锂负极导致的火灾、爆炸等安全风险使其难以走向实际应用。针对以上问题，本课题将对新结构、高性能纳米硫化锂/碳复合正极材料的结构功能定向设计与低成本可控构筑技术策略进行系统研究，结合理论模拟方法与前沿实验手段揭示材料合成、结构性能调变及电化学应用的多级多尺度过程机理机制，匹配不含金属锂的高比容量负极材料，建立高能量、高安全性的无金属锂锂硫电池关键材料及器件创制新技术、新理论，解决制约锂硫电池实用化面临的若干关键科学问题。

发展高性能、绿色环保的锂二次电池是我国发展新能源汽车产业、解决能源与环境可持续发展问题的重大战略需求。锂硫电池是近年来备受瞩目的新型高能量锂二次电池技术之一，但因在易燃电解液中使用金属锂负极导致的火灾、爆炸等潜在安全风险极大限制了其实际应用。本项目基于廉价无机锂盐与有机碳源前驱体之间的原位化学转化反应，建立了高容量纳米硫化锂/碳复合正极材料的结构功能定向设计与低成本制备策略，发展了基于高活性硫化锂正极的新型无金属锂锂硫电池，联用原位X射线衍射、原位紫外-可见光谱、原位阻抗谱、原位拉曼等谱学等多种先进分析技术揭示了多硫化物介导的氧化还原反应机制及电催化效应影响规律，并将本项目中电催化领域的基础积累拓展到低能耗海水电解制氢技术领域。项目执行期间在Nature Commun. 、Angew. Chem. Int. Ed.、Energy Environ. Sci.、Adv. Energy Mater.、Adv. Funct Mater.、ACS Nano、Nano Energy、J. Energy Chem.等国内外高水平学术期刊发表论文16篇，影响因子>10论文13篇, ESI高被引论文3篇，论文SCI他引1310余次，H因子50。获2019年辽宁省自然科学一等奖、2020年中国化工学会侯德榜化工科学技术青年奖、2020年中国颗粒学会青年颗粒学奖。培养研究生6人。