Nickel layered double hydroxide, Ni(OH)2, has been widely used as the cathode for nickel based battery systems. However, the currently commercialized β-Ni(OH)2 is limited by its low capacity. In contrast, α-Ni(OH)2 can give higher capacity, but it is challenging to stabilize in alkaline solution due to the conversion to β-Ni(OH)2. Herein, we use zinc doped Ni(OH)2 and control its spherical morphology to strengthen the stability of α-Ni(OH)2 in a nickel metal hydride battery system. With an optimal zinc doping content of 3 mol% for the spherical α-Ni(OH)2 (Ni-Zn3), the cathode shows the highest discharge capacity of 351.3 mAh g–1 at a current density of 70 mA g–1 (0.2 C) and superior rate performance, which even delivers 271.5 mAh g–1 at 5 C. More importantly, the durability of the Ni-Zn3 cathode is significantly enhanced, which maintains 81.7% after cycling 360 times, almost twice as long as that of pure α-Ni(OH)2. Studies show that the stabilized Ni–O bond and suitable aperture structure are mainly responsible for the advanced electrochemical properties of the Ni-Zn3. The results show that proper zinc doping spherical α-Ni(OH)2 with low-cost and high performance is an promising cathode material for nickel-based battery systems.

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We propose an aqueous copper battery via Cu2+/Cu+ and Cu3+/Cu2+ redoxes conversion chemistry on an activated carbon (AC) electrode enabled by a 30 m ChCl + 1 m CuCl2 electrolyte,...

LaFeO3 as a new negative electrode material for nickel-hydrogen batteries used as energy storage has the advantages of high capacity, advanced temperature resistance, and low cost. However, its conductivity and dynamic performance are poor, seriously hindering its applications. In light of increasing concentration of oxygen vacancies and improving conductivity after replacing A-site elements of the material, here we synthesize low-priced Na doping LaFeO3 oxides, La1−x Na x FeO3 (x = 0–0.8), as the negative electrode by a solid-state reaction method. Studies show that doping Na can reduce particle aggregation, thus helping to increase the surface area of LaFeO3. Therefore, its discharge capacity remarkably increases to 356.7 mAh g–1 (x = 0.6) from 178.8 mAh g–1 (x = 0) at 60 °C, which also maintains 73.4% after 100 cycles for La0.4Na0.6FeO3, elevated by 55.1% compared to LaFeO3. In addition, the high rate discharge ability of an La0.4Na0.6FeO3 electrode at a discharge current density of 1500 mA g–1 reaches 30.7% in contrast to 11.2% for undoped LaFeO3. As such, the La0.4Na0.6FeO3 material with superior cycling capacity is proven to be a more promising electrochemical hydrogen storage electrode compared to LaFeO3, which greatly increases the practical application value of the material.

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