Transient freezing strategy of metastable lithium titanate for high performance lithium-ion battery anodes under high pressure

Abstract

Lithium-ion batteries (LIBs) with a solid-solution or single-phase intercalation mechanism are considered to be excellent candidates for fast charging and addressing range anxiety, as they have few kinetic energy barriers apart from ion diffusion. In this regard, we capture metastable lithium titanate using High-Pressure High-Temperature (HPHT) synthesis technique under thermodynamic control in only 30 min. Compared with most conventional synthesis methods in the field, the preparation time is only 1.6–3.6% of them. Interestingly, stable and controllable structural defects can be induced under high pressure. Additionally, the HPHT-induced “fracture” structure significantly improves the kinetics of electrolyte storage and exhibits a remarkable pseudocapacitance of up to 89.1%. After 1000 cycles at 10 C, it still retains a reversible capacity of 165 mAh g−1 with a capacity retention rate of 97%. The capture of metastable phase by HPHT technology provides a new perspective and approach for material optimization and design.