Construction of symmetric aqueous rechargeable battery with high voltage based on NiFe2O4 hollow microspheres

• A new symmetric rechargeable battery based on NiFe2O4 was assembled.
• NiFe2O4 hollow microspheres were prepared through a hydrothermal route.
• The cathode and anode undergo respective redox pairs.
• An average working voltage of 1.3 V is achieved in aqueous electrolyte.

A new symmetric aqueous rechargeable battery was assembled by utilizing NiFe2O4 hollow microspheres as electrode materials. In this device, the cathode and anode use the same material, but undergo respective redox reaction due to the well-separated redox pairs of NiFe2O4. This new battery possesses a high working voltage of 1.3 V and a capacity of 26 mAh g− 1 based on the total mass of active materials.