大容量热电池二维硫钼片基正极材料微观结构调控及放电机理研究

Thermal battery is an important direction in the field of intellectualization of weapon system since it has long storage life, excellent performance in extreme temperature and mechanical environment, and high specific power. The disadvantages of conventional cathode materials of thermal battery, such as low discharge capacity and poor thermal stability, lead to develop new kinds of cathodes. A new idea of using layered molybdenum disulfide as cathode materials of thermal battery is proposed in this project. The key scientific problems to be solved are the regulation of microstructure of molybdenum disulfide nanosheets, the electrode reaction mechanism and the discharge process control. The research needed to be carried out are as follows: To explore the effects of experimental conditions of hydrothermal method on the microstructure of MoS2 nanosheet, to reveal the growth mechanism of MoS2 nanosheet, and to put forward one method to assemble the MoS2-nanosheet based material with three-dimensional microstructure. To regulate the electronic structure of MoS2 nanosheet by element doping and surface modification methods, and to establish the relationship of electronic structure and the intrinsic properties of MoS2. To explore the electric layer microstructure at the interface through theoretical calculation, in situ observation and performance testing, to reveal the mechanism of electron transfer. To explore the effects of experimental conditions on the discharge performance of thermal battery, screen a new kind electrochemical system using novel MoS2-nanosheet based materials as cathode for large capacity thermal battery. The project aims to provide a theoretical basis for the development of new technology of intelligent weapons.

热电池贮存寿命长、耐极端温度和力学环境、比功率高，是武器系统智能化技术发展的关键。针对热电池常规正极材料存在的放电能力低、热稳定性差等问题，本项目提出了大容量热电池用二维MoS2纳米片构筑三维纳微分级结构正极材料的新思路。围绕MoS2纳米片性能调控及电极反应机理关键科学问题，开展如下研究：探索水热合成实验条件对MoS2纳米片微观结构的影响规律，揭示MoS2纳米片生长机理，建立一种MoS2纳米片基三维纳微结构组装新方法；采用面内元素掺杂和表面修饰进行MoS2纳米片电子结构的调控，建立MoS2电子结构与本征性能间构效关系；从理论计算、原位观测和性能测试三个方面，探索电极/电解液界面微观结构，揭示电子转移机制；探索实验条件对热电池放电性能的影响规律，提出一种采用MoS2纳米片基三维纳微分级结构作为正极的大容量热电池用电化学新体系，为智能武器新技术的发展奠定理论基础。

热电池贮存寿命长、耐极端温度和力学环境、比功率高，是武器系统智能化技术发展的关键。针对热电池常规正极材料存在的放电能力低、热稳定性差等问题，本项目构筑了大容量热电池用硫钼基电化学新体系，围绕大容量热电池用新型硫钼基正极材料的开发与应用，采用理论计算与实验研究相结合的研究方法，从硫化钼材料的可控制备、掺杂硫化钼的可控制备及硫钼基正极材料在热电池中的应用等方面开展研究，最终提出一种热电池用新型正极材料，实现热电池容量的提升。主要研究内容有：①开展了硫化钼的可控制备，研究了合成温度、还原剂、合成时间、反应物种类等合成条件对材料微观形貌的影响，探索了不同微观形貌对正极材料热稳定性、与电解质的相容性的影响规律；分析并揭示了花球状MoS2微球生长机理：成核过程、MoS2纳米片生长过程和花球自组装过程；②采用第一性原理建立不同掺杂元素（Ti、V、Cr、Mn、Fe、Co、 Ni、W）和不同掺杂浓度（4%和11%）的MoS2超晶胞模型，探索了单相掺杂元素和双相掺杂元素对硫化钼形成能、结构、能带结构、态密度等性能的影响；开展了掺杂硫化钼的可控制备，研究了反应温度、硫源种类、钴钼比、表明活性剂等合成条件对材料微观形貌的影响，探索了不同微观形貌对正极材料热稳定性、与电解质的相容性的影响规律；分析并揭示了钴掺杂硫化钼材料的生长机理；③通过压片工艺的探索和优化，得到成型性较好的单体电池片；进行了MoS2及掺杂硫化钼热电池的放电性能测试，揭示了热电池中硫化钼和钴掺杂硫化钼的放电机理。依托于该项目研究成果，进一步进行了硫化钼基正极材料成品热电池的装配，从材料本身的表征结果和电池的放电性能测试结果来看，自组装硫钼基材料是一种具有潜力的热电池正极材料，有望应用于以热电池为电能源的智能弹药武器系统。