生物分子对金属负极枝晶抑制及其界面保护机制之探究

与石墨，硬碳以及高分子等碳基负极材料相比，金属负极因为具有更低的相对电极电势，极高的充放电理论容量，更高的使用效率而饱受青睐。相比较传统的二次电池，直接采用金属负极的电池往往拥有更高的充放电容量，更高的能量密度以及更高的工作电压，这些，正是下一代动力电池研发所需的基本需求。然而自诞生以来，金属负极就一直受到固态电解质相界面（SEI）膜的不稳定，活性材料损失，电解液易分解，循环稳定性差等不利影响。不仅如此，由于金属离子的不均匀沉积而产生的金属枝晶极易刺穿电池隔膜从而导致电池的内部短路甚至造成热失控以至爆燃等安全隐患。为此，本项目拟通过在电池中引用广泛存在于自然界中的生物分子，通过其调控负极界面，在降低金属负极安全隐患的同时，有效提升金属负极电池的能量密度并延长电池的使用寿命。最终通过此项目中的探究，生物分子在电化学储能中直接运用的丰富潜能将被深入挖掘且被系统地探讨。

Compared with carbon based anode materials such as graphite, hard carbon and polymers, metal anodes are favored for their lowest relative electrode potential, ultra-high theoretical capacity and higher efficiency. Compared with the traditional secondary battery, batteries directly using metal anode normally have higher charge-discharge capacity, higher energy density and higher working voltage, which have been regarded as important demands of the next generation energy storage technology. However, since their birth, metal anodes have been suffering from several obstacles, such as the instability of solid electrolyte interphase (SEI), the loss of active materials, electrolyte decomposition and poor cycle stability. Moreover, in the process of high current charging, the metal dendrites generated by the uneven deposition of metal ions can easily pierce the battery separator, resulting in the internal short circuit of the battery, thermal runaway and even deflagration. Therefore, this project plans to directly employ biological macromolecules which are widely existing in nature, into batteries. Through their complex and rich chemical structure, we plan to reduce the potential safety hazard of metal anodes, effectively improve the energy density of metal anode battery and prolong the service life of the batteries. At last, the potential of biomacromolecules in electrochemical energy storage will be deeply explored and systematically discussed.