Quenching‐Induced Defects Liberate the Latent Reversible Capacity of Lithium Titanate Anode. Issue 5 (23rd December 2022)

• Record Type: Journal Article
• Authors: Su, Zhong; Li, Shunning; Ma, Lu; Liu, Tongchao; Li, Meng; Wu, Tianpin; Zhang, Qinghua; Dong, Cheng; Lai, Chao; Gu, Lin; Lu, Jun; Pan, Feng; Zhang, Shanqing
• Is Part Of: Advanced materials. Volume 35:Issue 5(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-23
• Subjects: intrinsic defects -- lithium titanate anodes -- quenching -- reversible Li extraction; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202208573
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Interest in defect engineering for lithium‐ion battery (LIB) materials is sparked by its ability to tailor electrical conductivity and introduce extra active sites for electrochemical reactions. However, harvesting excessive intrinsic defects in the bulk of the electrodes rather than near their surface remains a long‐standing challenge. Here, a versatile strategy of quenching is demonstrated, which is exercised in lithium titanate (Li4 Ti5 O12, LTO), a renowned anode for LIBs, to achieve off‐stoichiometry in the interior region. In situ synchrotron analysis and atomic‐resolution microscopy reveal the enriched oxygen vacancies and cation redistribution after ice‐water quenching, which can facilitate the native unextractable Li ions to participate in reversible cycling. The fabricated LTO anode delivers a sustained capacity of 202 mAh g −1 in the 1.0–2.5 V range with excellent rate capability and overcomes the poor cycling stability seen in conventional defective electrodes. The feasibility of tuning the degree of structural defectiveness via quenching agents is also proven, which can open up an intriguing avenue of research to harness the intrinsic defects for improving the energy density of rechargeable batteries. Abstract : Intrinsic defects in quenched lithium titanate anodes enable reversible extraction of Li ions that are unextractable in pristine state, thus facilitating these native Li ions to participate in electrochemical cycling, which leads to a sustained capacity of 202 mAh g −1 in the 1.0–2.5 V range with excellent rate capability and cycling stability.