Nano-sized LiMri_2O_4 spinel cathode materials exhibiting high rate discharge capability for lithium-ion batteries

摘要

Nano-sized LiMri_2O_4 spinel with well crystallized homogeneous particles (60nm) is synthesized by a resorcinol-formaldehyde route. Micro-sized LiMn_2O_4 spinel with micrometric particles (1 靘) is prepared by a conventional solid-state reaction. These two samples are characterized by XRD, SEM, TEM, BET, and electrochemical methods. At current rate of 0.2C (1C-148mAg~(-1)). a discharge capacity of 136mAhg~(-1) is obtained on the nano-sized LiMn_2O_4, which is higher than that of micro-sized one (103 mAh g~'). Furthermore, compared to the micro-sized sample, nano-sized LiMn_2O_4 shows much better rate capability, i.e. a capacity of 85 mAhg~(-1),63% of that at 0.2C, is realized at 60C. The excellent high rate performance of nano-sized LiMn_2O_4 spinel may be attributed to its impurity-free nano-sized particles, higher surface area and well crystalline. The outstanding electrochemical performances demonstrate that the nano-sized LiMn_2O_4 spinel will be the promising cathode materials for high power lithium-ion batteries used in hybrid and electric vehicles.