Abstract: Li4Ti5O12 (LTO)-based battery has been considered as next generate energy storage battery for grid applications due to its excellent rate cyclic properties and cycle life. But up to now there is no capacity fading model which is suitable for LTO-based battery has been reported. We tested commercial LTO battery (nominal capacity of 10 A·h, 2.2～3.2 V rating). The cells were tested at different rate for more than 4800 cycles, the irreversible capacity loss of battery was measured at 0.1 C to eliminate the polarization effect after each 600 cycles. The test data was then used to develop an empirical model by curve-fitting and regression techniques. It can be used to predict the rated capacity loss due to polarization and irrevisible capacity loss caused by loss of active lithium.

Key words: grid energy storage battery, Li4Ti5O12, capacity fading model, charge/discharge rate, Peukert equation.