Binding Li3PO4 to Spinel LiNi0.5Mn1.5O4 via a Surface Co‐Containing Bridging Layer to Improve the Electrochemical Performance. Issue 8 (7th June 2021)

• Record Type: Journal Article
• Authors: Wu, Yida; Ben, Liubin; Zhan, Yuanjian; Yu, Hailong; Qi, Wenbin; Zhao, Wenwu; Huang, Xuejie
• Is Part Of: Energy technology. Volume 9:Issue 8(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-07
• Subjects: cathode-electrolyte interphase -- coatings -- Li3PO4 -- LiNi0.5Mn1.5O4 cathodes -- surface bridging layers; Energy development -- Periodicals; Power resources -- Periodicals; 333.79
• DOI: 10.1002/ente.202100147
• Languages: English
• ISSNs: 2194-4288

Abstract

Abstract : Coating the surface of cathode materials with Li3 PO4 to improve the cycling performance is commonly practiced; however, obtaining an effective and uniform coating of Li3 PO4 on cathode materials is extremely difficult due to the lack of strong bonds between them. Herein, this issue is solved by coating the surface of LiNi0.5 Mn1.5 O4 with Li3 PO4 via a novel hydrothermal method. It is shown that a uniform Li3 PO4 surface coating can only be obtained by introducing a small amount of additional metal ions, such as Co, in the starting solution. X‐ray photoelectron microscopy combined with scanning transmission electron microscopy reveals that the Co ions diffuse into the 16c sites of the surface of the spinel LiNi0.5 Mn1.5 O4 structure, making the surface layer act as a bridging layer that connects olivine Li3 PO4 with bulk spinel LiNi0.5 Mn1.5 O4 . The high‐voltage LiNi0.5 Mn1.5 O4 half‐cell with the optimal Li3 PO4 coating shows a discharge capacity retention of 95.8% after 50 cycles at 55 °C, compared with the only 81.1% discharge capacity retention of the bare counterpart. Abstract : Li3 PO4 is successfully and uniformly coated on the surface of the spinel LiNi0.5 Mn1.5 O4 via diffusion of Co ions into the surface structure of LiNi0.5 Mn1.5 O4 to form a bridge layer which bonds both materials.