Li₄Ti₅O₁₂-Based Battery Energy Storage System with Dual-Phase Cathode

Lithium-ion batteries with spinel Li₄Ti₅O₁₂ materials as anode, which can offer fast charge times, high power output, superior safety, and long life, are considered to be a competitive choice for grid-scale energy storage systems (ESS). Herein, a 10 Ah lithium–titanate battery with lithium cobalt oxide–lithium nickel cobalt manganese oxide dual-phase cathode is developed and its application in 100 kWh-level ESS is investigated. The 10 Ah single battery demonstrates a specific capacity of 79 Wh kg⁻¹ with a high-capacity retention rate of 91.8% after 1000 cycles at 55 °C and >80% capacity retention at 15 C_cell. The 125 kWh ESS shows an energy efficiency of 97.82% and 89.97% at 0.2 and 1.5 C_System, respectively. Self-discharge and constant power tests indicate that the battery system is stable, thus suitable for storing intermittent power from renewable sources such as solar and wind. The system's ability of smoothing the fluctuated power is confirmed by coordinating with a wind power system.