Tackling the Interfacial Issues of Spinel LiNi0.5Mn1.5O4 by Room-Temperature Spontaneous Dediazonation Reaction

Ranehipura Dewage Lahiru Sandaruwan; Lina Cong; Lipo Ma; Shunchao Ma; Hongyu Wang

doi:10.1021/acsami.1c00204

Tackling the Interfacial Issues of Spinel LiNi_0.5Mn_1.5O₄ by Room-Temperature Spontaneous Dediazonation Reaction

ACS Appl Mater Interfaces. 2021 Mar 24;13(11):13264-13272. doi: 10.1021/acsami.1c00204. Epub 2021 Mar 9.

Authors

Ranehipura Dewage Lahiru Sandaruwan^{1

2}, Lina Cong³, Lipo Ma⁴, Shunchao Ma¹, Hongyu Wang^{1

2}

Affiliations

¹ State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
² School of Applied Chemistry and Engineering, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, P. R. China.
³ National & Local United Engineering Laboratory for Power Battery, Department of Chemistry, Northeast Normal University, Changchun 130024, P. R. China.
⁴ Fuel Cell System and Engineering Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, P. R. China.

PMID: 33687207
DOI: 10.1021/acsami.1c00204

Abstract

The detrimental interfacial side reactions, inducing electrolyte decomposition and transition-metal dissolution, are regarded as "arch-criminal" for the utilization of spinel LiNi_0.5Mn_1.5O₄ (LNMO) in high-power Li-ion batteries (LIBs). To conquer this issue, herein, we construct a thin polyphenyl film onto the surface of LNMO via the spontaneous dediazonation of C₆H₅N₂⁺BF₄^- at room temperature. This conductive film facilitates the Li⁺ transport within cathode and at LNMO|electrolyte interface while reinforcing the compatibility of LNMO against electrolyte by efficiently suppressing the electrolyte decomposition catalyzed by LNMO and even the transition-metal dissolution. Consequently, polyphenyl-grafted LNMO exhibits improved electrochemical performances, e.g., the considerable discharge capacity of 136.7 mAh g^-1 at low current density (0.1C), excellent rate capability, and long-term cyclability with a reversible capacity of 107.4 mAh g^-1 along with high capacity retention of ∼85% after cycling 500 times, that are superior to those of the pristine LNMO counterpart. All these results demonstrate that our strategy is instrumental in solving the interface issues with respect to the spinel LNMO cathode, impelling the development of LNMO-based batteries with high energy density.

Keywords: LiNi0.5Mn1.5O4 cathode; interfacial issues; lithium-ion batteries; spontaneous dediazonation; surface polyphenyl modification.