New Type of Alkaline Rechargeable Battery—Ni-Ni Battery

The feasibility of utilizing disordered Ni-based metal hydroxide, as both the anode and the cathode materials, in alkaline rechargeable batteries was validated for the first time. Co and Mn were introduced into the hexagonal Ni(OH)2 crystal structure to create disorder and defects that resulted in a conductivity increase. The highest discharge capacity of 55.6 mAh ̈g ́1 was obtained using a commercial Li-ion cathode precursor, specifically NCM111 hydroxide, as anode material in the Ni-Ni battery. Charge/discharge curves, cyclic voltammetry (CV), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy dispersive spectroscopy (EDS) analysis, and electron energy loss spectroscopy (EELS) were used to study the capacity degradation mechanism, and the segregation of Ni, Co, and Mn hydroxides in the mixed hydroxide. Further optimization of composition and control in micro-segregation are needed to increase the discharge capacity closer to the theoretical value, 578 mAh ̈g ́1.