Artificial CEI modification for spinel lithium manganate and its high temperature performance
Spinel lithium manganate cathode material for lithium-ion battery possess the advantages of cost-effec-tiveness and high safety. However,the high voltage platform of lithium manganate is higher,thus resulting in a thick cathode-electrolyte interphase (CEI) and increasing the polarization. In addition,the degradation of battery cycle performance due to the dissolution of manganese also seriously restricts its application at high temperature.In this study,the problems of side reactions and manganese dissolution were solved by improving the electro-chemical stability of electrolyte/electrode interface by modifying the lithium manganate cathode material with ar-tificial CEI. By applying lithium silicate as the artificial CEI coating layer,the first cycle coulomb efficiency of the full cell at 60 ℃ is increased by 11.2％,and the dissolution rate of manganese at 60 ℃ is decreased by 10.9％. The capacity retention of the lithium manganate/graphite full battery after 1 000 cycles is increased from 62.2％ to 83.5％. In addition,through the detection of manganese residue on the surface of the graphite anode,it is found that the electrochemical performance improvement is attributed to the inhibition of the dissolution of manganese in the positive electrode and the reduction of manganese residue on the negative electrode. The strate-gy of applying lithium silicate as an artificial CEI modification provides an effective way to improve the high temperature performance of spinel lithium manganate cathode materials.
lithium manganateCEI filmlithium silicatehigh temperature performanceLIB
NETL
NSTL
万方数据
