前驱体热处理温度对LiNi1/3Co1/3Mn1/3O2材料的影响

以NaCO3为沉淀剂,NH3·H2O为缓冲溶液,将NiSO4、CoSO4和MnSO4混合溶液共沉淀制备（Ni1/3Co1/3Mn1/3）CO3前驱体,将其在400-900℃热处理5h制备得（Ni1/3Co1/3Mn1/3）Ox氧化物。EDTA络合滴定、BET、XRD及SEM研究表明,随着热处理温度的升高,（Ni1/3Co1/3Mn1/3）Ox中过渡金属含量及结晶度随着增加,而比表面积却减小。（Ni1/3Co1/3Mn1/3）Ox与LiOH混合后在850℃热处理24h制备出LiNi1/3Co1/3Mn1/3O2材料,其结构、形貌及电性能的测试结果表明,前驱体在600℃条件下热处理制备的正极材料电化学性能最佳,其首次放电比容量为189.7mAh·g^-1,不同倍率循环60周后,循环保持率为92.4%。

Effects of Precursor Heat-treated Temperature on LiNi1/3Co1/3Mn1/3O2 Materials

The （Ni1/3Co1/3Mn1/3）CO3 precursor was obtained by co-precipitation method using Na2CO3 as a precipitator and NH3·H2O as a buffer solution, in a mixed solution of NiSO4、CoSO4 and MnSO4. The precursor was sintered at various temperatures （400-900℃）for 5 h to synthesize （Ni1/3Co1/3Mn1/3）Ox oxides, which were investigated by EDTA titration, BET, XRD and SEM. The results indicated that with the increasing of heat-treatet tempreture, the content of the metal and the crystallinity increased, while the specific surface area decreased. The LiNi1/3Co1/3Mn1/3O2 cathode materials were synthesized via sintering the mixture of （Ni1/3Co1/3Mn1/3）Ox oxides and LiOH at 850℃ for 24 h. The structures, morphologies and electrochemical properties were tested, and the results indicated that the LiNi1/3Co1/3Mn1/3O2 cathode material synthesized by the precursor sintered at 600℃ had best electrochemical properties. Its initial discharge capacity was 189.7mAh·g^-1. The cycle retention was 92.4% after 60 cycles at various rate capacity.