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Inspired by the functional properties of ion defect induction and charge compensation in defect engineering, these methods are expected to be an effective strategy to solve the constraints of Li4Ti5O12 (LTO) inherent conductivity and diffusion dynamics, and further improve battery rate performance. The oxygen vacancy (OV) content in LTO can be controlled quantitatively by high‐pressure induction using the high‐pressure and high‐temperature (HPHT) method. In addition, the relationship between the electrochemical properties and OV is further explored. The theoretical calculations indicate that the OV defects cause the electrons to delocalize into the conduction band of the LTO, and thus fundamentally improve the intrinsic conductivity. In particular, the high‐pressure quenching strategy of HPHT causes LTO to instantly produce crack holes with massive crystalline layers, which can be regarded as storage for the electrolyte to facilitate ion diffusion. The fabricated LTO anodes containing OVs compensate for the limitation of the poor rate performance with a capacity of 176 mAh g−1 at 20 C. Pressure‐induced OV defects not only open up a new perspective in the field of lithium‐ion batteries (LIBs), but also provide a certain degree of freedom for the functional design characteristics of defect engineering. [ABSTRACT FROM AUTHOR]

• Metastable lithium titanate can be trapped and frozen by high-pressure dynamics. • The preparation of samples via high-pressure synthesis only takes 30 minutes, and the cost is 1.6–3.6% that of traditional solid-state sintering. • The pressure causes the lattice oxygen to escape and leaves the oxygen vacancy defects in the matrix. • The induced structural defects under controlled pressure can significantly improve the lithium storage performance and electrochemical performance. 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. [Display omitted] [ABSTRACT FROM AUTHOR]

Due to the fact that the diffusion of ions in lithium titanate is mainly controlled by the diffusion kinetics of metastable intermediates along the twisted octahedral interface, it is possible to obtain high-performance titanium-based anodes via adding more alternative diffusion paths or increasing the contact probability between lithium ions and lithium polyhedral. Here, Li 4 Ti 5 O 12 (LTO) is modified with a metastable phase Li 2 Ti 3 O 7 containing twisted octahedron as an additive, and the composites (denoted as LTO-C) with superior diffusion kinetics are obtained via high-pressure and high-temperature (HPHT) technology. Interestingly, the effect of high pressure causes lattice oxygen escape and generates abundant structural defects in the LTO-C sample, which significantly ameliorates the insufficient conductivity of the titanium-based anodes while providing more energy storage sites for charge transfer. LTO-C demonstrates a reversible capacity of 185 mAh g−1 at a current density of 2000 mA g−1. This technology provides a new pathway for the preparation of composite materials and inspires the functional design of energy materials. [Display omitted] • The additive Li 2 Ti 3 O 7 can change the charge and discharge characteristics of Li 4 Ti 5 O 12. • The composite phase of lithium titanate can be intercepted in only 30 min under high pressure. • The defect electrode has superior lithium storage and electrochemical performance. [ABSTRACT FROM AUTHOR]