Ni3Se2 and Co-doped Ni3Se2 cauliflower-like nanostructures are synthesized using a simple and feasible electrochemical deposition technique. Electrochemical measurements of the resultant nanostructures in 1 M KOH electrolyte solution revealed that the energy storage performance of the cauliflower-like Ni3Se2 nanostructures was considerably improved by cobalt doping. Particularly, 6 wt% Co-doped Ni3Se2 electrodes exhibited remarkable high specific capacity (179.34 mAh g−1) and excellent stability with capacity retention of 85.9% over 1000 cycles because of their high electrical conductivity. Furthermore, to verify the feasibility of the optimized Co-doped Ni3Se2 electrodes for practical applications, Zn ion batteries were constructed by using a Zn plate as the anode and the Co-doped Ni3Se2 nanostructures as the cathode. The constructed Zn ion battery achieved high energy and power densities of 199.34 W h kg−1 and 24,510 W kg−1 at the current densities of 1 and 20 A g−1, respectively. In addition, up to 2.2 electrons per formula unit of Ni3Se2 were successfully utilized, indicating considerably higher utilization of Ni2+/Ni3+ redox sites by Co doping the selenite. This work demonstrated an effectual strategy for rational design of highly robust, low-cost flexible electrodes for energy storage devices.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MIST) ( NRF-2016R1E1A1A01941978 ). HDY and KK were supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MIST) ( NRF-2018R1C1B6004808 ) and Pusan National University Research Grant, 2017.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology