以球形α-Ni_(0.8)Co_(0.2)(OH)_2制备锂离子电池正极材料LiNi_(0.8)Co_(0.2)O_2

Preparation of LiNi_(0.8)Co_(0.2)O_2 Cathode Material for Lithium Secondary Batteries from Spherical α-Ni_(0.8)Co_(0.2)(OH)_2

ＬｉＮｉ０．８Ｃｏ０．２Ｏ２是很有希望取代ＬｉＣｏＯ２的新一代锤离子电池正极材料．采用控制结晶法合成球形 α－Ｎｉ０．８Ｃｏ０．２（ＯＨ）２为前驱体，与 ＬｉＯＨ·Ｈ２Ｏ混合，在７００℃通Ｏ２热处理４ｈ合成锂离子电池正极材料ＬｉＮｉ０．８Ｃｏ０２Ｏ２粉末．Ｘ光衍射分析表明合成的ＬｉＮｉ０．８Ｃｏ０．２Ｏ２粉末结晶良好，具有规整的α－ＮａＦｅＯ２层状结构．扫描电镜分析表明粉末颗粒呈球形，粒径约８μｍ．粉末的流动性好，堆积密度高．充放电测试表明，合成的 ＬｉＮｉ０．８Ｃｏ０．２Ｏ２正极材料具有优良的电化学性能：首次充电比容量为１９７ｍＡｈ·ｇ－１，放电比容量为１７４ｍＡｈ·ｇ－１，１０次充放电循环后保持初始放电比容量的９６．６％．

LiNi0.8Co0.2O2 cathode material is a very promising candidate to replace LiCoO2 for lithium secondary batteries. Spherical α-Ni0.8Co0.2(OH)2 powders were prepared via a 'con- trolled crystallization' method. The LiNi0.8Co0.2O2 powders were synthesized by sintering the α-Ni0.8Co0.2(OH)2 precursor and LiOH·H2O in oxygen at 700℃ for 4h. XRD results show the powders are highly crystallized LiNi0.8Co0.2O2 with order α－NaFeO2 layer structure. SEM photographs show the powders are spherical dispersed particulate with the particle size of approximately 8μm. The powders have good fluidity and high tap-density Electrochemical test proves the LiNi0.8Co0.2O2 cathode material has excellent electrochemical performance. The material shows a high initial charge capacity of 197mAh·g-1 and discharge capacity of 174mAh·g-1, and retention of more than 96.6% after 10 cycles.