A novel sheet perovskite type oxides LaFeO3 anode for nickel-metal hydride batteries

Abstract

Compared with traditional hydrogen storage alloys, perovskite oxide LaFeO3 materials are considered as one of the most promising anode materials for nickel-metal hydride batteries owing to their low cost, environmental friendliness, and superior temperature resistance. However, the biggest problem faced by perovskite oxide LaFeO3 as an anode material for Nickel/metal hydride (Ni-MH) batteries is the low electrical conductivity and poor specific capacity, which is mainly due to the serious agglomeration phenomenon in its structure. To solve the above problems, lamellar LaFeO3 material with large specific surface area and small particle size has been synthesized by adding N,N-Dimethylformamide (DMF) and polyvinyl pyrrolidone (PVP) inhibitor materials to the precursor. By changing the sintering temperature, the lamellar composite LaFeO3 material can be controlled. Consequently, the maximum discharge capacity of lamellar LaFeO3 is up to 372.1 mA h g–1 at the discharge current density of 60 mA g–1. Meanwhile, after 100 cycles, the specific discharge capacity of the lamellar LaFeO3 can still reach 293.1 mA h g–1, which is much higher than that of 98.5 mA h g–1 for LaFeO3. In addition, the kinetics of LaFeO3 has been investigated and the lamellar LaFeO3 shows excellent dynamic properties. Notably, the exchange current density I0 (300 mA g–1) of the layered LaFeO3 electrode is higher than that of LaFeO3 (150 mA g–1). Overall, this work provides insights into a structure-performance relationship for the further development of high-performance perovskite-type oxide nickel-metal hydride battery anodes.