Simultaneous High Ionic Conductivity and Lithium-Ion Transference Number in Single-Ion Conductor Network Polymer Enabling Fast-Charging Solid-State Lithium Battery

Developing solid-state electrolyte with sufficient ionic conduction and flexible-intimate interface is vital to advance fast-charging solid-state lithium batteries. Solid polymer electrolyte yields the promise of interfacial compatibility, yet its critical bottleneck is how to simultaneously achieve high ionic conductivity and lithium-ion transference number. Herein, single-ion conducting network polymer electrolyte (SICNP) enabling fast charging is proposed to positively realize fast lithium-ion locomotion with both high ionic conductivity of 1.1 x 10(-3) S cm(-1) and lithium-ion transference number of 0.92 at room temperature. Experimental characterization and theoretical simulations demonstrate that the construction of polymer network structure for single-ion conductor not only facilitates fast hopping of lithium ions for boosting ionic kinetics, but also enables a high dissociation level of the negative charge for lithium-ion transference number close to unity. As a result, the solid-state lithium batteries constructed by coupling SICNP with lithium anodes and various cathodes (e.g., LiFePO4, sulfur, and LiCoO2) display impressive high-rate cycling performance (e.g., 95% capacity retention at 5 C for 1000 cycles in LiFePO4|SICNP|lithium cell) and fast-charging capability (e.g., being charged within 6 min and discharged over than 180 min in LiCoO2|SICNP|lithium cell). Our study provides a prospective direction for solid-state electrolyte that meets the lithium-ion dynamics for practical fast-charging solid-state lithium batteries.

Automated summary

Developing solid-state electrolyte with sufficient ionic conduction and flexible-intimate interface is crucial for fast-charging solid-state lithium batteries. In this study, a single-ion conducting network polymer electrolyte (SICNP) is proposed to achieve fast lithium-ion locomotion with high ionic conductivity and lithium-ion transference number. The construction of polymer network structure in SICNP facilitates the fast hopping of lithium ions and enables a high dissociation level of the negative charge for close to unity lithium-ion transference number. The solid-state lithium batteries constructed with SICNP and various cathodes exhibit impressive high-rate cycling performance and fast-charging capability. Our study provides a prospective direction for practical fast-charging solid-state lithium batteries.