Ion-conductive protective layer–integrated lithium metal anodes via high-current electrodeposition under ambient pressure

Abstract

Lithium metal is a highly attractive anode for next-generation high-energy-density batteries, however, the practical fabrication of thin lithium anodes via electrodeposition is severely constrained, since it is typically conducted at low current densities and under high external pressures to suppress dendritic growth. Here, we report an ion-conductive protective layer (ICPL)-assisted electrodeposition strategy that enables uniform, dendrite-free lithium deposition at high current densities under ambient pressure. The ICPL, composed of Li+-conductive Li6.4La3Zr1.4Ta0.6O12 particles and an elastomeric dual-polymer binders, provides high ionic conductivity, a high Li+ transference number, and mechanical resilience. This combination allows stable lithium electrodeposition at 6 mA cm−2 without external pressure, forming a dense lithium anode integrated with the protective layer. The ICPL-integrated anode shows stable cycling for over 400 h and a critical current density of 17 mA cm−2. In Li/LiNi0.8Co0.1Mn0.1O2 cells with an active cathode loading of 15 mg cm−2, a 20 μm ICPL-integrated lithium anode retains 82.9% of its initial capacity after 200 cycles at 45 °C, outperforming cells using commercial rolled lithium metal. This work presents a scalable route for fabricating thin, high-performance lithium metal anodes under practical conditions.