共沉淀法制备球形镍锰复合草酸盐的最佳pH值

Optimum pH Value for Preparing Spherical Multiple Oxalate of Nickel-Manganese by Co-precipitation Method

由共沉淀法合成了锂离子电池正极材料LiNi_(1/2)Mn_(1/2)O_2用球形镍锰复合草酸盐前驱体。通过对M^(2+)-(Ni^(2+),Mn^(2+))-NH_3-C_2O_4^(2-)-H_2O体系的热力学分析,得到了M^(2+)-NH_3-C_2O_4^(2-)-H_2O体系的lg[M^(2+)]-pH关系图(其中M为过渡金属元素),从而得出了以NH_4OH为络合剂、H_2C_2O_4为沉淀剂,采用共沉淀法制备球形镍锰复合草酸盐的最佳共沉淀pH值为8.2。在此pH值条件下合成的镍锰复合草酸盐粉料呈球形,且分散较好。

A precursor spherical multiple oxalate of nickel-manganese of Li-ion battery cathode material LiNi1/2 Mn1/2O2 is synthesize by the co-precipitation method. According to the thermodynamic analysis of M2＋ （Ni2＋ , Mn2＋ ）-NH3-C2O4^2--H2O system,the curves about lg[M2＋ ]-pH of M2＋ （Ni2＋ , Mn2＋ ）-NH3-C2O4^2--H2O systerm is obtained. The most suitable condition of pH value for preparing spherical multiple oxalate of nickel-manganese using N H4 OH as eomplexing agent, C2H2O4 · 2H2O as precipitant is 8. 2. The shape of the precursor powder is expected sphere,