Effect of electrolytic MnO2 pretreatment on performance of as-prepared LiMn2O4
(1. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
2. Powder Metallurgy Research Institute, Central South University, Changsha 410083, China;
3. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)
2. Powder Metallurgy Research Institute, Central South University, Changsha 410083, China;
3. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)
Abstract: To investigate the effect of electrolytic MnO2 (EMD) on the performance of LiMn2O4, several pretreatment methods, such as acid treating, presintering and impregnating with chromic salt, were used. The pretreated EMD and prepared LiMn2O4 were characterized by X-ray diffraction and inductively coupled plasma emission spectrometry. Charge and discharge tests of Li/LiMn2O4 batteries were also employed to evaluate electrochemical performance. The experimental results show that inorganic impurity contents in EMD decrease remarkably after acid treating; presintering EMD can remove adsorbent water and organic impurity, enlarge pore space and increase active reaction sites; pre-doping chromium in EMD can form more homogenous compound substance LiCr0.05Mn1.95O4, which shows better structural stability and capacity retention.
Key words: lithium-ion batteries; cathode material; LiMn2O4; MnO2