A kind of cathode material of layered LixNiyMn1- yO2 characterized with the O2 type has been synthesized by a simple method. Its precursor NaxNiyMn1- yO2 has been prepared from manganese dioxide, nickel hydroxide and ...A kind of cathode material of layered LixNiyMn1- yO2 characterized with the O2 type has been synthesized by a simple method. Its precursor NaxNiyMn1- yO2 has been prepared from manganese dioxide, nickel hydroxide and sodium carbonate at high temperature in air and quickly cooled in cold water, then it has been exchanged by the melted LiNO3 at 300～ 400℃ in air. The effects of calcine temperature for the precursors and its compositions (the content of Na and Ni) on the electrochemical properties of the material LixNiyMn1- yO2 have been investingated by XRD and electrochemical tests. The results show that the sample Li0.7Ni0.3Mn0.7O2, has the best electrochemical properties which shows only one charge discharge potential stage of 2.8～ 3.0V and has a high specific capacity over 180mAh· g- 1 cycled between 2.0～ 4.20V. A significant structure transformation to the spinal type phase has not been found in the charge discharge cycling and the discharge specific capacity around 165mAh· g- 1 has remained after the 20th cyclings for the material.展开更多
研究了丁二酮肟沉淀分离-乙二胺四乙酸二钠滴定法测定LiCoxNiyMn1-x-yO2(0<x,0<y,x+y<1)中镍含量,得到准确快速测定镍含量的最佳操作条件为:加入30 ml 15%酒石酸溶液、20 ml 50%乙酸铵溶液,沉淀时的pH=6.5、陈化时间为0 min;...研究了丁二酮肟沉淀分离-乙二胺四乙酸二钠滴定法测定LiCoxNiyMn1-x-yO2(0<x,0<y,x+y<1)中镍含量,得到准确快速测定镍含量的最佳操作条件为:加入30 ml 15%酒石酸溶液、20 ml 50%乙酸铵溶液,沉淀时的pH=6.5、陈化时间为0 min;采用电位滴定法准确快速测定锰;提出以二甲酚橙为指示剂,在pH值为6.0～6.2的六次甲基四胺缓冲介质中、100℃下,以EDTA滴定法测定镍、锰和钴的总量,利用差减法推算出钴含量。本方法的相对标准偏差小于0.71%,回收率为97.40%～101.60%,耗时不到60 min,实现了LiCoxNiyMn1-x-yO2中镍、钴、锰的准确快速测定。展开更多
文摘A kind of cathode material of layered LixNiyMn1- yO2 characterized with the O2 type has been synthesized by a simple method. Its precursor NaxNiyMn1- yO2 has been prepared from manganese dioxide, nickel hydroxide and sodium carbonate at high temperature in air and quickly cooled in cold water, then it has been exchanged by the melted LiNO3 at 300～ 400℃ in air. The effects of calcine temperature for the precursors and its compositions (the content of Na and Ni) on the electrochemical properties of the material LixNiyMn1- yO2 have been investingated by XRD and electrochemical tests. The results show that the sample Li0.7Ni0.3Mn0.7O2, has the best electrochemical properties which shows only one charge discharge potential stage of 2.8～ 3.0V and has a high specific capacity over 180mAh· g- 1 cycled between 2.0～ 4.20V. A significant structure transformation to the spinal type phase has not been found in the charge discharge cycling and the discharge specific capacity around 165mAh· g- 1 has remained after the 20th cyclings for the material.
文摘研究了丁二酮肟沉淀分离-乙二胺四乙酸二钠滴定法测定LiCoxNiyMn1-x-yO2(0<x,0<y,x+y<1)中镍含量,得到准确快速测定镍含量的最佳操作条件为:加入30 ml 15%酒石酸溶液、20 ml 50%乙酸铵溶液,沉淀时的pH=6.5、陈化时间为0 min;采用电位滴定法准确快速测定锰;提出以二甲酚橙为指示剂,在pH值为6.0～6.2的六次甲基四胺缓冲介质中、100℃下,以EDTA滴定法测定镍、锰和钴的总量,利用差减法推算出钴含量。本方法的相对标准偏差小于0.71%,回收率为97.40%～101.60%,耗时不到60 min,实现了LiCoxNiyMn1-x-yO2中镍、钴、锰的准确快速测定。
