Dual Functions of Carbon in Li 4 Ti 5 O 12 /C Microspheres

Abstract

© 2014 The Author(s). Spinel Li 4 Ti 5 O 12 has become an alternative material to replace graphite anodes in terms of solving safety issues and improving battery life-time. Unfortunately, as Li 4 Ti 5 O 12 is an insulator, the low electrical conductivity becomes a major drawback, as it is unfavorable to higher rate capability. In addition to the low electronic conductivity, severe gassing during charge/discharge cycles is a critical but often-overlooked problem of Li 4 Ti 5 O 12 batteries. Li 4 Ti 5 O 12 /C microspheres were prepared by assembling the nano- Li 4 Ti 5 O 12 (50-300 nm) with pitch derived pyrolytic carbon. It was found that the coated carbon in Li 4 Ti 5 O 12 /C microspheres can effectively inhibit gassing and Mn deposition in LiMn2O4//Li 4 Ti 5 O 12 battery. Carbon can also significantly improve rate capability and cycling performance comparedwith that of Li 4 Ti 5 O 12 microsphereswithout carbon due to stable interface and superior electronic conductivity.