Building more secure LMBs with gel polymer electrolytes based on dual matrices of PAN and HPMC by improving compatibility with anode and tuning lithium ion transference

Abstract

Li metal is considered as a “Holy Grail” anode material for Li metal batteries (LMBs). Unfortunately, the interface problems including the interface reaction of lithium metal anode and the generation of lithium dendrite between lithium metal anode and electrolyte are still the major obstacles in the practical application of LMBs. Here, a novel gel polymer electrolyte (GPE) is attempted to solve these issues. The membrane of polymer composite matrix is successfully prepared by blending hydroxypropyl methyl cellulose (HPMC) with polyacrylonitrile (PAN) through a simple phase inversion method, and finally the corresponding GPE is obtained by an activation process in electrolyte. The polymer composite membrane overcomes some shortcomings of traditional PAN matrix, and meanwhile the corresponding GPE exhibits superior electrochemical performances. As a result, an ultralong-term reversible lithium plating/stripping cycle at a moderate current density (1 mA cm−2) with dendrite-free is achieved for lithium metal anodes. The full cell test results show a higher reversible capacity (106 mAh g−1) at 2C, capacity retention (94.2%) after 100 cycles and a stable coulomb efficiency (98.9%). This study emphasizes the capacity of the designed GPE in stabilizing lithium metal anode and opens a new perspective on the synergy of between different materials.