Synthesis Of Ni（OH）₂/RGO Composites And Its Electrochemical Properties

Ni-MH batteries as a high-energy rechargeable battery, high capacity, power andpollution-free characteristics, has become the object of competing research is important forthe future direction of development of the secondary battery.The positive active electrodematerial of Nickel-hydrogen battery that is Ni(OH)2and cathode electrode active materialis rare hydrogen storage alloy. in recent years, cathode active material develop more andmore rapid, the cathode electrode capacity has been greatly improved, reached1600mAh·g-1,while the theoretical capacity of traditional β-Ni(OH)2electrode material isonly289.4mAh·g-1, so the Ni-MH battery capacity was severely restricted by the anodeelectrode material.In this paper, The positive active electrode material of Nickel-hydrogen battery areresearched and discussed about its development; as well as discuss the applicationof reduction graphene on the electrode materials. Especially, the preparation of reductiongraphene as the substrate synthesis Ni(OH)2/RGO composite as electrode materials.Graphite as precursor, a good degree of oxidation of graphite oxide was synthesisusing Hummers method. The GO can be dispersed with a large number ofoxygen-containing functional groups under ultra-sonicoscillation at ID water.Using graphite oxide and nickel nitrate hexahydrate as precursor, while hydrazinehydrate is reductant, Ni(OH)2/RGO composites were successfully synthesis.Grapheneas precursor on a simple chemical precipitation method, and we researched the effect ofdifferent proportions of GO and Ni(OH)2to the structure and performance of thecomposites. The electrochemical tests showed that Ni(OH)2/RGO with a mass proportionsof1:8showed the best discharge property with348.5mAh·g-1at0.2C ratio specificdischarge capacity and excellent cycle performance. Furthermore, L9(34) orthogonal experiment design were conducted to investigate theinfluence of the temperature、a mass ratio、the precipitation agent、reducing agent. Theresults show that The four factor order effect of reducing agent, precipitating agent, massratio, temperature of the composite material discharge capacity. When the reactiontemperature is100℃, the quality ratio of1:12, precipitating agent for urea, sodiumborohydride as reducing agent, get α/β-Ni(OH)2/RGO composite material, its discharge at0.2C rate than the capacity of388.9mAh·g-1; When the hydrothermal reaction temperatureis100℃, the mass ratio of1:8, precipitation agent, ammonia water reducingagent for thiourea dioxide, get β-Ni (OH)2/RGO composites at0.2C rate discharge capacityis up to341mAh·g-1and the10C discharge rate can still reach242.2mAh·g-1. The cyclicvoltammetry shows, which can effectively improve the nickel anode in oxygenevolution potential, thus inhibiting the oxygen evolution reaction on the sideeffect ofcharging process, and ultimately improve the utilization rate of the nickel electrode activematerial and improve charging efficiency, Ni(OH)2high current chargedischarge performance of.