多孔聚合物在锂金属负极保护中的研究进展

Lithium metal batteries (LMBs) are regarded as one of the most promising candidates for next-generation high-energy-density devices, due to the high theoretical specific capacity and low electrochemical potential of lithium metal anode. However, the uncontrollable growth of Li dendrite, unstable Li/electrolyte interface and infinite volume fluctuation during charge/discharge process give rise to low Coulombic efficiency, poor cycle stability and even serious safety hazard from internal short-circuit via dendrite penetration through separators. These multifaceted problems severely hinder the practical applications of LMBs. Featured by high specific surface area, low density, controllable pore structure, and flexible molecular design of pore surface/skeleton functionality, porous polymers have received growing attention in electrochemical energy storage, especially for lithium anode protection. The nanopores and tailored functionalities could allow for facilitated Li ion transport, while inhibiting anions and regulating the grain size and distribution of LiF. The large pores are conducive to accommodating lithium deposition and lowing of local current density. Consequently, porous polymers have become the "new favorite" in the field of "dendrite-free" LMBs recently, which show great potential for stabilizing Li metal anode. However, explorations in this field still remain in their infancy, and the objective of this review is to briefly summarize the research progress of porous polymers, especially crystalline covalent organic frameworks for lithium metal anodes protection, by means of constructing the artificial solid electrolyte interphase layer, coating separator with functional layers and designing metal anode structure.