Highly porous LiMnPO4 in combination with an ionic liquid-based polymer gel electrolyte for lithium batteries

A porous well defined LiMnPO4 cathode material is synthesized by a sol-gel method. The electrochemical performance of the cathode material is evaluated in a cell with an ionic liquid-based polymer electrolyte (0.5 M LITFSI in EMImTFSI) and a lithium metal electrode. The results are compared to a cell with a traditional organic carbonate-based electrolyte (1 M LiPF6 in EC/DMC). The cell with the ionic liquid-based polymer electrolyte presents an enhanced electrochemical intercalation performance of lithium ions, a high electrochemical stability window of 5 V, and an excellent cycling ability as compared with the organic based counterpart. Furthermore, the ionic liquid-based polymer gel electrolyte effectively prevents the dissolution of manganese — otherwise a common problem.

► A porous well defined LiMnPO4 cathode material is synthesized by a sol-gel method.
► The LiTFSI/EMImTFSI based polymer electrolyte was prepared by electrospinning.
► The interconnected structure of LiMnPO4 is built up by particles in the range 30-50 nm.
► The conductivity of the polymer electrolyte is above 10-3 S/cm at 0 ̊C.
► Mn dissolution into the polymer electrolyte was found to be less than 5 ppm.