A high performance Li-rich β-Li 2 IrO 3 electrode for symmetric lithium ion batteries

The symmetric battery composed of single electrode material as both 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 narrow choice of suitable electrode materials limits the practicable deployment of high-performance symmetric batteries. Herein, we report a novel Li-rich β-Li2IrO3 (LIO) symmetric electrode material with a reversible capacity of >200 mAh g-1 between 3.0−4.8 V (LIO-cathode) and >300 mAh g-1 between 0.1–3.0 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 intergrity and stability, leading to the outstanding cycling life of both LIO-cathode and anode. Additionally, the full symmetric lithium ion battery (LIB) using LIO as both the anode and cathode exhibited a high reversible capacity of 160 mAh g-1 between 2.0–4.5 V with a high working potential of 3.5 V.