A binary PMMA/PVDF blend film modified substrate enables a superior lithium metal anode for lithium batteries

Abstract

Metallic lithium is a promising next generation electrode material due to its ultrahigh specific capacity and lowest redox potential. However, its short cycling lifespan and safety hazards have hindered its practical application. To improve the cycling performance of lithium metal anodes, dendrite-free lithium deposition and a stable electrode–electrolyte interface are of vital importance. Here, we prepared a thin PMMA/PVDF gel coating using an electrospinning technique on a Cu substrate as the anode directly, which can not only homogenize lithium ion flux, promoting uniform lithium deposition, but can also alleviate the dramatic volume change in the lithium anode, improving the stability of the electrode interface. Owing to the excellent lithiophilic properties and high mechanical flexibility of the binary blend polymer coating, stable cycling for over 1400 h is achieved in a Li/Li symmetric cell using modified coating at 1 mA cm⁻² with a cycling capacity of 1 mA h cm⁻². The binary blend polymer coating with complementary properties prepared by this facile method provides a new insight for the lithium metal anode improvement.