大容量VB_2-空气电池负极材料的制备与性能

Preparation and Discharge Performance of Porous VB_2 Anodes for High Capacity VB_2-air Battery

VB_2因具有超高理论比容量(4060 m Ah/g)而成为具有发展潜力的空气电池负极材料。实验以VB_2为负极活性物质,Ni为导电剂,NH_4HCO_3为造孔剂,采用粉末冶金方法制备了大容量VB_2-空气电池用多孔负极片,并探讨了负极片孔隙度对负极所组装空气电池放电性能的影响规律。结果表明,所制备的多孔VB_2负极片放电性能优异,放电比容量可以达到3216~3463 m Ah/g范围内;多孔VB_2负极片放电容量、比容量、库伦效率和比能量均与孔隙度密切相关。当添加15wt%NH_4HCO_3造孔剂时,烧结制备的多孔VB_2负极片的孔隙度为60.91%,此时VB_2-空气电池放电性能最优:放电容量为7792 m Ah,放电比容量为3463 m Ah/g,库伦效率为85.30%,放电比能量为2370 mWh/g。

VB2 has great potential as an anode material of air batteries due to its high theoretical specific capacity （4060 mAh/g）. In present work, the porous anodes for high capacity VB2-air battery were prepared by using powder metallurgy technology, with VB2 as the active materials of anodes, Ni as the conductive agents, and NH4HCO3 as the space-holder. The effect of porosity on the discharge performances of porous anodes was investigated. The results show that the porous anodes exhibit a good discharge performance with specific capacity up to 3216-3463 mAh/g. The discharge capacity, specific capacity, coulombic efficiency, and specific energy all significantly depend on the porosity of the porous anodes. When the addition of space-holder NH4HCO3 is 15wt%, the porous anodes have the porosity of 60.91%, and possess the superior discharge properties with discharge capacity of 7792 mAh, specific capacity of 3463 mAb_/g, coulombic efficiency of 85.30%, and specific energy of 2370 mWh/g.