A high performance Li-rich β-Li2IrO3 electrode for symmetric lithium ion batteries

A symmetric battery composed of a single electrode material as both the anode and cathode is a model battery configuration owing to its distinctive advantages over the existing asymmetric ones in terms of cost, production process and safety issues. However, the limited choice of suitable electrode materials limits the practical application of high-performance symmetric batteries. Herein, we report a novel Li-rich β-Li2IrO3 (LIO) symmetric electrode material with a reversible capacity of >200 mA h g−1 between 3.0 and 4.8 V (LIO-cathode) and >300 mA h g−1 between 0.1 and 3.0 V (LIO-anode), respectively. The synthesized LIO materials manifested a unique three dimensionally (3D) ordered hyperhoneycomb-like structure that endows the material with enhanced structural integrity and stability, leading to an outstanding cycle life of both the LIO-cathode and anode. Additionally, the symmetric full lithium ion battery (LIB) using LIO as both the anode and cathode exhibited a high reversible capacity of 160 mA h g−1 between 2.0 and 4.5 V with a high working potential of 3.5 V.