反尖晶石LiNiVO_4的湿法低温合成

Inverse Spinel LiNiVO_4 Synthesized by Moist Method at Low Temperature

In this paper, we report a new kind of moist chemical method for preparing LiNiVO 4 which can be used to prepare lithium ion battery for the cathode active materials with a very high battery voltage(48 V vs. Li). Li 2CO 3, NiCO 3 and NH 4VO 3 were used as row materials, and H 2C 2O 4 saturated solution was used both as a precipitate agent and as a complex agent. The precursor gel composed of (NH 4) 2(VO) 2(C 2O 4) 4·6H 2O, NiC 2O 4·2H 2O and Li 2C 2O 4 can be obtained, and after sintering the dry gel we got the products. The results of XRD show that the product sintered at 400 ℃ for 2 h exists in a cubic crystal, single phase, inverse LiNiVO 4 and the average sizes (by Scherrer formula ) were 40—50 nm(400 ℃, 2 h ) and 65—70 nm(700 ℃, 2 h) , respectively, a=0.822 3(1) nm. The TG and DTA curves implied that the dry gel underwent water loss, decompositions of oxalates and complex oxalate, the solid state reactions finished at 377 ℃. The results of XPS proved that the valence in LiNiVO 4 would be Li+,V 5+ , Ni 2+ (in the main), respectively. From ICP analysis we also knew that the sample corresponded basically to stoichiometry LiNiVO 4 .