Abstract
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.
Highlights
The first Ni(OH)2 -based alkaline rechargeable batteries, Ni-Fe and Ni-Cd, were patented by Thomas A
(transition metal) batteries extended into Ni-Zn and Ni-Co systems
Electrochemical Measurements two ternaries were prepared by the continuous stirring tank reactor (CSTR) process
Summary
The first Ni(OH)2 -based alkaline rechargeable batteries, Ni-Fe and Ni-Cd, were patented by Thomas A. Many works have been done to improve the performance of rechargeable batteries [3,4,5]. The half-cell reactions at positive and negative electrodes and the full cell reaction are shown in Equations (1)–(3), respectively (where Mt is a transition metal, for example Fe or Cd). NipOHq2 ` OHé NiOOH H2 Oe ́ pforward : charge, reverse : dischargeq (1). Mt pOHq2 ` 2NipOHq2 é Mt 2NiOOH 2H2 O pforward : charge, reverse : dischargeq (3). The negative electrode uses the transformation of a transition metal between the +2 and 0 oxidation states during charge/discharge operation. During the last two decades, the Ni-TM (transition metal) batteries extended into Ni-Zn and Ni-Co systems. The common features of these rechargeable batteries are low-cost and wide working temperature ranges. The reaction in Equation (2) involves a two-electron transfer (resulting in a very high theoretical capacity, see Table 2), the utilization of active material is not Batteries 2016, 2, 16; doi:10.3390/batteries2020016 www.mdpi.com/journal/batteries
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
