Organic Composite Materials with Enhanced Cycling Stability and High-Rate Performance as Anodes for Aqueous Mg–Li Hybrid-Ion Batteries

Aqueous metal-ion batteries (AMIBs) are considered one of the potential energy-storage devices because of their high safety and low cost. Compared with traditional single-metal-ion (such as Mg or Li ion) AMIBs, the aqueous hybrid-ion batteries, such as Mg–Li hybrid-ion batteries (AMLIBs), exhibit improved Coulombic efficiency and long-term cycling stability owing to the co-intercalation/deintercalation of Mg2+ and Li+. In this study, organic polymer composite anode materials (PNTAQ@CNTs-5.7% and PNTAQ@rGO-4.4%) are designed and synthesized for AMLIBs, and they show excellent electrochemical performance characterized by up to 3000 cycles and nearly 100% Coulombic efficiency. The AMLIB full cell assembled with PNTAQ@CNTs-5.7% as the anode and Mg2MnO4 as the cathode has a power density of 63.7 Wh kg–1 under extremely high power density of 7674.7 W kg–1, which shows great promising potential in the development of practical aqueous batteries.