The constructed potential-pH diagrams of Li-Ni(Co,Mn)-H_(2)O system indicate that the LiNiO_(2),LiCoO_(2)and LiMnO_(2)are thermodynamically stable in aqueous solution within the temperature range of 25-200℃and the ac...The constructed potential-pH diagrams of Li-Ni(Co,Mn)-H_(2)O system indicate that the LiNiO_(2),LiCoO_(2)and LiMnO_(2)are thermodynamically stable in aqueous solution within the temperature range of 25-200℃and the activity range of 0.01-1.00.A predominant co-region of LiNiO_(2),LiCoO_(2)and LiMnO_(2)oxides(Li-Ni-Co-Mncomposite oxide)is found in the Li-Ni-Co-Mn-H_(2)O potential-pH diagrams,in which the co-precipitation region expands towards lower pH with rising temperature,indicating the enhanced possibility of synthesizing Li-Ni-Co-Mn composite oxide in aqueous solution.The experimental results prove that it is feasible to prepare the LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)cathode materials(NCM523)by an aqueous routine.The as-prepared lithiated precursor and NCM523 both inherit the spherical morphology of the hydroxide precursor and the obtained NCM523 has a hexagonalα-NaFeO_(2)structure with good crystallinity.It is reasonable to conclude that the aqueous routine for preparing NCM cathode materials is a promising method with the guidance of the reliable potential-pH diagrams to some extent.展开更多
基金Project(FA2019015)supported by the Government of Chongzuo,Guangxi Zhuang Autonomous Region,ChinaProject(AD18281073)supported by Science and Technology Department of Guangxi Zhuang Autonomous Region,China
文摘The constructed potential-pH diagrams of Li-Ni(Co,Mn)-H_(2)O system indicate that the LiNiO_(2),LiCoO_(2)and LiMnO_(2)are thermodynamically stable in aqueous solution within the temperature range of 25-200℃and the activity range of 0.01-1.00.A predominant co-region of LiNiO_(2),LiCoO_(2)and LiMnO_(2)oxides(Li-Ni-Co-Mncomposite oxide)is found in the Li-Ni-Co-Mn-H_(2)O potential-pH diagrams,in which the co-precipitation region expands towards lower pH with rising temperature,indicating the enhanced possibility of synthesizing Li-Ni-Co-Mn composite oxide in aqueous solution.The experimental results prove that it is feasible to prepare the LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)cathode materials(NCM523)by an aqueous routine.The as-prepared lithiated precursor and NCM523 both inherit the spherical morphology of the hydroxide precursor and the obtained NCM523 has a hexagonalα-NaFeO_(2)structure with good crystallinity.It is reasonable to conclude that the aqueous routine for preparing NCM cathode materials is a promising method with the guidance of the reliable potential-pH diagrams to some extent.
