Enhanced compatibility of a polymer-based electrolyte with Li-metal for stable and dendrite-free all-solid-state Li-metal batteries

Abstract

To meet the rapidly growing demand for high-energy storage, it will be crucial to develop high power all-solid-state Li-metal batteries (SS-LMBs). In SSLMBs, the solid-state electrolyte enables high performance and long-term cycling stability. To investigate, we employed a YNa zeolite as a ceramic filler and a large fraction of Li-salt to synthesize a solid composite polymer electrolyte (YNa-CPE) with an enhanced work function. This enabled the creation of a stable interfacial layer between the YNa-CPE and Li-metal and prevented the growth of Li-dendrites. The galvanostatic lithium plating and stripping analysis of a symmetric [Li|YNa-CPE|Li] cell was initially conducted at different current densities for more than 1500 h, revealing uniform overpotential, which confirmed no significant growth of lithium dendrites even after the application of high current density. The Li-ion transference number greatly improved to 0.84. An excellent ionic conductivity of 1.66 × 10⁻² S cm⁻¹ was achieved at 60 °C. A capacity of 156.63 mA h g⁻¹ was obtained (for the LFP cathode) at a Li-salt concentration of 35%, with a capacity retention rate of >95% over 100 cycles. By improving compatibility with the cathode, stability can be further improved. This investigation presents a facile tactic to fabricate superior performance and long-term stable SS-LMBs.