Enhancing the performance of ionic conductivity for solid-state electrolytes: an effective strategy of injecting lithium ions within anionic metal–organic frameworks†

Metal–organic frameworks (MOFs) are considered as potential solid-state electrolyte (SSE) materials due to their structural diversity and porosity. Adding lithium ions into the anionic frameworks of MOFs and then realizing single-ion transport is an efficient way to enhance the performance of ionic conductivity of SSE materials. Herein, an ionotropic MOF (Li⁺[Cu-BTC]⁻) with lithium ions in the pores of the lattice was synthesized through an ion exchange strategy, which exhibits outstanding lithium ionic conducting properties over a wide temperature range (ionic conductivity: 0.11–2.96 × 10⁻³ S cm⁻¹ in the temperature range of −40 to 100 °C). The strategy of injecting Li⁺ within anionic metal–organic frameworks provides a new opportunity for exploring advanced SSEs.