High‐Pressure Induction and Quantitative Regulation of Oxygen Vacancy Defects in Lithium Titanate

Abstract

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.

Luminescence-Monitored Progressive Chemical Pressure Implementation Realized through Successive Y3+ and Mg2+ Doping into Ca10.5(PO4)7:Eu2+

“…External pressure implementation has been conducive to exploration of new matters, , development of novel functionalities, , and realization of unprecedented performances. , Although external physical pressure, which is at the macroscale, has been utilized in a wide range of research areas, it not only requires a large platform, expensive facilities, and tedious operation, but it is also apt to cause particle agglomeration, form crystallographic defects, and thus affect unambiguous data interpretation. In a parallel manner, chemical pressure is at the nanoscale and is generated by selective doping of certain substances, such as metal cations , or nonmetal anions with different ionic radius or charges from those to be replaced, into expected positions of crystal lattices .…”

Ultrafast Catalytic Pyrolysis and Induction of High-Rate Artificial Defect Graphite under High Pressure

“…treated natural graphite in a CO 2 atmosphere to obtain graphite anodes with inherent lattice defects, exhibiting good rate performance . Prior to this, our team utilized HPHT technology to synthesize lithium titanate materials with oxygen vacancy defects, significantly improving rate and cycling performance. , However, there have been no literature reports on the rapid preparation of artificial graphite through catalytic pyrolysis under pressure.…”