Electrochemical behavior of NiCl2/Ni in acidic AlCl3-based ionic liquid electrolyte
Abstract
The electrochemical properties of nickel chloride as a cathode in basic electrolyte have been much examined, but little study has focused on those properties in acidic electrolyte. In this study, the electrochemical behavior of Al-NiCl2 in acidic AlCl3-EMIC ionic liquid electrolyte is investigated, confirming the reversible reaction between Ni(2) and Ni. The assembled cell delivers an initial discharge capacity of 115.0 mA h g−1 at 100 mA g−1, and it remains at 93.7 mA h g−1 over 100 cycles, with a Coulombic efficiency of 97.9%, displaying a high specific capacity with stable cycling performance. Additionally, the degradation mechanism of this cell is verified as the dissolution of partial Ni metal generated from the reduction of NiCl2 during discharging in the acidic electrolyte.