Electrochemical performance of single Li4Ti5O12 particle for lithium ion battery anode

摘要

Single particle measurement is a known characterization method for electrode materials. In a conventional single particle measurement, highly advanced techniques are necessary to electrically bring a microelectrode into contact with a single-particulate active material while observing with an optical microscope. Our measurement method doesn't require a high level of skill by using a "particle-current collector integrated microelectrode", in which the single active material particle was directly-contacted on the tip of the microelectrode by platinum deposition. In this study, the intrinsic properties of a conventional Li4Ti5O12 (LTO) single particle were investigated by using the integrated microelectrode without any binder and carbon additives. Cyclic voltammograms and charge-discharge profiles at various temperatures between 10 and 40 degrees C revealed that Li+ extraction (discharge) was faster than Li+ insertion (charge) because of the difference in Li+ diffusion into the single LTO particle, thereby exhibiting remarkable discharge capacity retention ( > 80%) even at 1000C and 10 degrees C. Cycle performance at charge-discharge rate of 30C showed excellent reversibility, in which capacity retention and Coulombic efficiency were estimated to be 96.4% and 99.97%, respectively, even after 5000 cycles.