【摘要】 采用控制结晶法制备锂离子电池用高密度球形正极材料LiNi0.8Co0.2O2。对前驱体Ni0.8Co0.2(OH)2制备工艺进行优化,在金属盐溶液流速为8 mL/min,搅拌速率450 r/min,pH值为11.5,氨浓度20 g/L反应36 h的条件下,合成了振实密度为2.02 g/cm3的球形Ni0.8Co0.2(OH)2。并以Ni0.8Co0.2(OH)2为原料,与LiOH.H2O进行混合研磨进行高温烧结,考察烧结制度对合成材料LiNi0.8Co0.2O2电化学性能的影响。在Li/(Ni+Co)配比为1.05、氧气流量为800 mL/min,750℃下烧结16 h所得材料LiNi0.8Co0.2O2电化学性能最优:在0.2 C,3.0~4.3 V的条件下,首次放电容量达到195.4 mA.h/g,循环50次后容量保持率达到89.2%。更多还原

【Abstract】 High-density spherical cathode material LiNi0.8Co0.2O2 powders for lithium secondary battery were prepared via a controlled crystallization method.Under the preparation conditions,when metal salt solution flow rate was 8 mL/min,stirring speed was 450 r/min,pH value was 11.5,ammonia concentration was 20 g/L and reaction time was 36 h,the spherical Ni0.8Co0.2(OH)2 powders with tap-density of 2.02 g/cm3 were obtained.The mixture of Ni0.8Co0.2(OH)2 and LiOH.H2O was sintered and the calcination process,especially sintering time and sintering temperature,was studied.LiNi0.8Co0.2O2 cathode material,which is synthesized with 1.05 Li/(Ni+Co) under 800 mL/min oxygen flow and 750 ℃ for 16 h,achieves a high initial discharge capacity of 195.4 mA?h/g at 0.2 C current between 3.0 and 4.3 V,and excellent capacity retention of 89.2% after 50 cycles.更多还原