Confining Liquid Electrolytes in a Nitrogen-Rich Nanoporous Carbon Sponge for Superior Lithium-Ion Conduction

Solid-state Li-ion batteries are recognized as highly promising energy storage devices due to their ability to overcome issues related to the inferior cycle life and potential risks of traditional liquid Li-ion batteries. However, developing solid-state electrolytes with fast Li-ion conductivity continues to be a major challenge. In this study, we present a family of quasi-solid-state electrolytes (QSSEs) synthesized by confining liquid electrolytes within a N-rich porous carbon sponge, exhibiting superior Li-ion conduction for solid-state battery applications. The N-rich porous carbon sponge was prepared by carbonizing ZIF-8 under an argon atmosphere, followed by the incorporation of organic liquid salt electrolytes into the pores and channels of the sponge to create composite QSSEs. Notably, the resulting composite QSSEs demonstrate exceptional Li-ion conduction at room temperature, with a record-high conductivity exceeding 10^-2 S cm^-1 and a remarkable Li⁺ transference number of 0.75, along with a wide electrochemical stability window of 4.8 V. Furthermore, these composite QSSEs show significant potential for use in solid-state Li-ion batteries, delivering a specific capacity of 133 mAh g^-1 at 0.1 C and possessing a high Coulombic efficiency of 98.6%.