Rechargeable hybrid aqueous batteries

Abstract A new aqueous rechargeable battery combining an intercalation cathode with a metal (first order electrode) anode has been developed. The concept is demonstrated using LiMn 2 O 4 and zinc metal electrodes in an aqueous electrolyte containing two electrochemically active ions (Li + and Zn 2+ ). The battery operates at about 2 V and preliminarily tests show excellent cycling performance, with about 90% initial capacity retention over 1000 charge–discharge cycles. Use of cation-doped LiMn 2 O 4 cathode further improves the cyclability of the system, which reaches 95% capacity retention after 4000 cycles. The energy density for a prototype battery, estimated at 50–80 Wh kg −1 , is comparable or superior to commercial 2 V rechargeable batteries. The combined performance attributes of this new rechargeable aqueous battery indicate that it constitutes a viable alternative to commercial lead-acid system and for large scale energy storage application.