Abstract
An aqueous sodium ion battery (ASIB) with metal Zn as anode and Na₄Mn₉O(18)-reduced graphene oxide (Na₄Mn₉O(18)-RGO) as cathode has been developed. In this work, spherical Na₄Mn₉O(18)-RGO composite particles were prepared via spray drying. The aqueous battery exhibits stable cyclability and high specific capacities. Typically, a high initial discharge capacity of 61.7 mAh·g(-1) is attained at a high current rate of 4 C, and a stabilizing reversible capacity of 58.9 mAh·g(-1) was obtained after 150 cycles. The network interlaced by RGO sheets provided fast electron conduction paths and structural stability to accommodate the mechanical stresses induced by sodium insertion and extraction, so the Na₄Mn₉O(18)-RGO electrode displayed superior electrochemical performance in the ASIB.