一种分散在多孔碳上的碳包覆硅负极的制备及应用

Carbon Coated Si Nanoparticles Dispersed in a Hierarchical Porous Carbon Framework for High Performance Lithium Ion Battery Anodes

硅负极具有高比容量的显著优势,其理论比容量(4200 mA·h/g)达到传统石墨负极的10倍以上,被认为是锂离子电池最有潜力的负极之一。然而,硅负极存在导电性较差、充放电过程中体积膨胀巨大等诸多问题,导致其循环性能较差,限制了大规模实际应用。本文提供了一种高性能硅负极的制备方法及应用,通过将硅负极分散在多级孔碳中,连同黏结剂聚丙烯腈涂覆在集流体上,再对极片进行热处理实现聚丙烯腈碳包覆,有效提高电极的整体导电性并能为巨大的体积变化提供空间,从而提升硅负极的大倍率性能和循环稳定性。

Si is one of the most promising anode materials for lithium-ion batteries owing to its high theoretical capacity,which is more than ten times higher than that of conventional graphite anodes.The main challenges associating with Si include its low conductivity and large volume change during cycling which lead to the decline of specific capacity.Herein,a novel structure with carbon coated Si nanoparticles embedded in the hierarchical porous carbon(HPC)framework was designed to effectively solve the issues of Si-based anodes.The overall conductivity of the electrode was effectively improved and void space for the Si expansion was provided,thus the rate capability and cycling performance of the silicon anode were promoted.