Role of disorder in limiting the true multi-electron redox in ε-LiVOPO4. Issue 42 (3rd October 2018)

• Record Type: Journal Article
• Authors: Rana, Jatinkumar; Shi, Yong; Zuba, Mateusz J.; Wiaderek, Kamila M.; Feng, Jun; Zhou, Hui; Ding, Jia; Wu, Tianpin; Cibin, Giannantonio; Balasubramanian, Mahalingam; Omenya, Fredrick; Chernova, Natasha A.; Chapman, Karena W.; Whittingham, M. Stanley; Piper, Louis F. J.
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 42(2018)
• Page Start: 20669
• Page End: 20677
• Publication Date: 2018-10-03
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8ta06469e
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Ball-milling-induced disorder and defects impede multi-electron redox in ε-LiVOPO4 and trigger side reactions. Abstract : Recent advances in materials syntheses have enabled ε-LiVOPO4 to deliver capacities approaching, and in some cases exceeding the theoretical value of 305 mA h g −1 for 2Li intercalation, despite its poor electronic and ionic conductivity. However, not all of the capacity corresponds to the true electrochemical intercalation/deintercalation reactions as evidenced upon systematic tracking of V valence through combined operando and rate-dependent ex situ X-ray absorption study presented herein. Structural disorder and defects introduced in the material by high-energy ball milling impede kinetics of the high-voltage V 5+ /V 4+ redox more severely than the low-voltage V 4+ /V 3+ redox, promoting significant side reaction contributions in the high-voltage region, irrespective of cycling conditions. The present work emphasizes the need for nanoengineering of active materials without compromising their bulk structural integrity in order to fully utilize high-energy density of multi-electron cathode materials.