Nitrogenized 2D Covalent Organic Framework Decorated Ni‐Rich Single Crystal Cathode to Ameliorate the Electrochemical Performance of Lithium Batteries

Abstract

Organic cathode materials for lithium‐ion batteries (LIBs) have elicited interest due to their wide‐ranging structures and finely regulated molecular levels. However, designing a cathode material with a high specific capacity, high rate‐performance, and long‐cycle life remains highly challenging. Herein, a nitrogenized 2D covalent organic framework (COF) with maximal active and minimal inactive groups is described and created by utilizing a coating material for single crystal LiNi0.78Mn0.12Co0.1O2 (SCNMC) cathodes for LIBs. The composite cathode delivers a high reversible capacity of 160.5 mAh g−1 at 1 C with a retention rate of 87.5% after 200 cycles. The cycled SCNMC@COF particles show no lattice gliding and micro‐cracks, demonstrating that the SC shape may considerably reduce anisotropic micro‐strain. This efficient, repeatable, and customizable method for producing SCNMC cathodes shall hasten their commercialization. The solid framework further ensures outstanding capacity retention and rate performance. According to density functional theory calculations, optimizing the loading of redox‐active groups in a stable network structure is an efficient technique for designing a stable structure and improving the cycling life of SCNCM cathode material.

Manganese and Cobalt-Free Ultrahigh-Ni-Rich Single-Crystal Cathode for High-Performance Lithium Batteries

“…Overall, a low polarization voltage displayed better Li + deintercalation performance, better reversibility, and lower impedance . Concerning the transition-metal dissolution mechanism and Li/Ni cation mixing, a deep analysis has been conducted in previous studies to compare the adverse effects of Ni, Mn, and Co on the electrochemical performances of Ni-rich cathodes. ,,− Previous research has suggested that Mn contributes to the preservation of the crystal structure and dissipates the internal strain from lattice volume changes more effectively than Co . As a result of the difference in Co–O bond length and an increase in atomic displacement inside the lattice during charge/discharge, the redox-active Co 3+ causes local strain.…”

Impact of Graphitization Degree on the Electrochemical and Thermal Properties of Coal

“…Graphite has been extensively studied as a carbon material for lithium-ion battery electrodes. Many scholars have used graphite for electrochemical testing by making lithium-ion batteries to test their electrochemical performance. − In this study, a liquid lithium-ion battery was used for electrochemical testing to examine electrochemical impedance and charge–discharge cycle. The electrochemical impedance reflects conductivity, while battery charging and discharging reflect the lithium storage and discharge capacities of the sample.…”

PVP-Assisted Hydrothermal Synthesis of Nickel-Rich Cobalt-Free Single-Crystal LiNi0.9Mn0.05Al0.05O2 for Lithium-Ion Batteries

“…32,34 The valence state of the transition metal significantly influences the structural stability of layered cathode materials. 35 XPS analysis was conducted to examine the chemical states of both P-NMA and S-NMA. Figure 4a displays the complete XPS spectra of both samples, revealing clear characteristic peaks corresponding to the elements Ni, Mn, Al, O, and C. The degree of Li + /Ni 2+ disorder is commonly associated with the Ni 2+ content on the sample surface.…”