A Low Temperature Self‐Assembled ZrO2 Layer as a Surface Modification for High Energy Density Ni‐Rich Cathode Materials in a Lithium‐Ion Battery. Issue 2 (6th January 2021)

• Record Type: Journal Article
• Authors: Ho, Van-Chuong; An, Hyejin; Hong, Meihua; Lee, Suhyun; Kim, Jineun; Park, Min Bum; Mun, Junyoung
• Is Part Of: Energy technology. Volume 9:Issue 2(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-01-06
• Subjects: combustion reactions -- full cells -- low heating temperatures -- Ni-rich layered cathodes -- self-assembled ZrO2 layers; Energy development -- Periodicals; Power resources -- Periodicals; 333.79
• DOI: 10.1002/ente.202000800
• Languages: English
• ISSNs: 2194-4288

Abstract

Abstract : Ni‐rich layered oxide cathodes are an immediately applicable alternative for meeting the high energy density demand of lithium‐ion batteries. The most significant hurdle of Ni‐rich layered cathode materials is their poor cyclability because of their increasing surface resistance due to their electrochemically reactive surfaces causing side reactions and the occurrence of Li/Ni cation mixing. Surface coating has been extensively studied for safeguarding particles, thereby leading to increases in electrochemical performance; however, the synthesis conditions must be carefully controlled due to the fragile surface of a Ni‐rich layered cathode. Herein, an effective coating method with self‐assembled ZrO2 (SA–ZrO2 ) on the surface of a Ni‐rich layered cathode material, LiNi0.82 Co0.09 Mn0.09 O2 (NCM82), through a low‐temperature self‐combustion reaction is proposed. SA–ZrO2 is built by a combustion reaction of Zr(SO4 )2 ·4H2 O and thioacetamide to improve the surface stability of the cathode. In addition, a very small content of SO x is retained from the precursor, which promotes high lithium diffusion on the surface. Systematic analyses by X‐ray photoelectron spectroscopy and transmission electron microscopy demonstrate that this highly homogeneous ZrO2 coating layer, which is prepared at a low temperature of 500 °C, largely enhances the electrochemical performance in the half‐cell and full‐cell. Abstract : The surface modification for Ni‐rich cathode materials is required for homogeneous coating layers, without Ni 2+ /Li + cation mixing in the reheating process. Herein, a homogeneous ZrO2 layer forms on the surface of NCM82 Ni‐rich cathode materials through self‐combustion reaction, leading to the ZrO2 layer forming at a low temperature, whereby the bulk structure of NCM82 materials is preserved.