Stabilize Lithium Metal Anode through Constructing a Lithiophilic Viscoelastic Interface Based on Hydroxypropyl Methyl Cellulose

Abstract Due to higher theoretical specific capacity and lower electrochemical redox potential, lithium metal is considered an ideal anode material for high specific energy batteries. However, safety problems related to the uncontrolled growth of lithium dendrites and the volume expansion of lithium have hindered its commercialization. This paper reports a viscoelastic interface based on viscoelastic polymer (hydroxypropyl methyl cellulose) to protect lithium metal anode. The lithiophilic interface has good chemical, electrochemical and mechanical stability, which makes the dendrite-free and low volume expansion lithium possible. The Li/Li symmetrical battery based on anode protected by viscoelastic interface show better cycle stability and longer cycle life. The morphologies after cycles show a relatively smooth and dense lithium deposition. Li/LFP full battery test results show higher reversible capacity at higher C-rate, high capacity retention (85.2%) and stable coulomb efficiency (99.5%) at 0.2 C after 200 cycles. This work provides insight into the strategy of interfacial engineering to protect lithium metal anode.