Highly elastic and low resistance deformable current collectors for safe and high-performance silicon and metallic lithium anodes

Abstract

Silicon and lithium metal are promising anode materials toward high energy densities Li (ion) batteries. However, silicon and lithium generally have dramatic volume change during lithiation/delithiation cycles. With the repeated expansion/shrinkage, the internal stress fluctuations and electrode pulverization can cause high interfacial resistance and the failure of electrodes. Herein, a novel strategy is proposed to engineer the current collector by using a polydopamine-assisted electroless metallization process to prepare an elastic deformable current collector covered with a high electrical conductivity Cu nano-network surface. The deformable current collectors can not only stabilize the interfacial stress as an artificial-spring, but also improve the electrical conductivity of anodes without any binders and conductive agents. Featured with outstanding deformable structure, the well-designed current collector achieves a low surface resistance of 0.06 Ω/sq and excellent electrochemical performance when applied in the commercial Si anode batteries, solid-state batteries, and ionic liquid electrolyte batteries at room-temperature.