Electrochemistry and safety of Li4Ti5O12 and graphite anodes paired with LiMn2O4 for hybrid electric vehicle Li-ion battery applications

A promising anode material for hybrid electric vehicles (HEVs) is Li4Ti5O12 (LTO). LTO intercalates lithium at a voltage of ∼1.5 V relative to lithium metal, and thus this material has a lower energy compared to a graphite anode for a given cathode material. However, LTO has promising safety and cycle life characteristics relative to graphite anodes. Herein, we describe electrochemical and safety characterizations of LTO and graphite anodes paired with LiMn2O4 cathodes in pouch cells. The LTO anode outperformed graphite with regards to capacity retention on extended cycling, pulsing impedance, and calendar life and was found to be more stable to thermal abuse from analysis of gases generated at elevated temperatures and calorimetric data. The safety, calendar life, and pulsing performance of LTO make it an attractive alternative to graphite for high power automotive applications, in particular when paired with LiMn2O4 cathode materials.

► Safety and performance of Li5Ti4O12 and graphite anodes paired with LiMn2O4 cathodes.
► Cycle life and calendar life of Li5Ti4O12 outperforms LiMn2O4.
► Graphite generates flammable gases and has lower onset temperature than Li5Ti4O12.
► Li5Ti4O12/LiMn2O4 chemistry is candidate for high power battery applications.