A team from Japan’s AIST and Ishihara Sangyo Kaisha, Ltd. has developed a new titanium oxide material—H2Ti12O25—that exhibits 28.5% higher energy capacity than lithium titanate (Li4Ti5O12, LTO). Additionally, the team developed a synthesis method that can be used at a relatively low temperature of 200-300 °C.
|Charge-discharge curve of the new material vs. LTO. Click to enlarge.|
The new material features a capacity of 225mAh/g, compared to LTO’s 175 mAh/g. According to AIST, the material can lower costs because it does not contain lithium.
The new material shows cycling properties similar to those of LTO. After 50 cycles, charging capacity and service capacity were 213 mAh/g and 212 mAh/g, respectively—almost the same as the levels after 10 cycles.
Sodium titanate (Na2Ti3O7) is used as a starting material. An acid treatment is applied to it at a temperature of 60 °C to make H2Ti3O7 as a precursor. Subsequent heating to 200-300°C forms H2Ti12O25.