High temperature investigation of electrochemical lithium insertion into Li4Ti5O12

High Pressure Rapid Synthesis of LiCrTiO4 with Oxygen Vacancy for High Rate Lithium-Ion Battery Anodes

Lithium-ion battery based on LiCrTiO₄ (LCTO) is considered to be a promising anode material, as they provide higher safety and durability beyond than that of graphite electrode. However, the applications of this transformative technology demand improved inherent electrical conductivity of LCTO as well as a simple and rapid synthetic route. Here, LCTO with oxygen vacancies (OVs) is fabricated using high-pressure synthesis technology in only 40 min. The optimal synthesis pressure is 0.8 GPa (LCTO-0.8). The reversible capacity of LCTO-0.8 at 1C is 131 mA h g^-1 after 1000 cycles and the capacity retention is nearly 97%, and the reversible capacity of LCTO synthesized at atmospheric pressure (LCTO-P) is 85 mA h g^-1 under the same circumstances. Even at 5C, the reversible capacity is 110 mA h g^-1 , which is 77% higher than LCTO-P. Furthermore, it is confirmed by theoretical calculations that the introduction of OVs has the occupation of electronic states at the Fermi level, which greatly enhances the intrinsic conductivity of LCTO. Specifically, the electronic conductivity has increased by two orders of magnitude compared with LCTO-P. Therefore, high-pressure synthesis technology endows LCTO with superior characteristics, providing a new avenue for industrialization.