High Voltage‐Stabilized Graphdiyne Cathode Interface

Abstract

Suppressing the irreversible interfacial reactions is an important scientific bottleneck in the development of stable high‐energy‐density lithium‐ion battery. The interfacial chemistry of graphdiyne (GDY) on the high‐voltage cathode of LiNi0.5Mn1.5O4 (LNMO) shows a very interesting process, in which the sp‐hybridization carbon atoms chemically scavenge the hydrofluoric acid (HF) and in situ form the fluorinated GDY interface. It first turns the harmful HF into profit, and greatly enhances the interfacial stability and restrains the side reaction on the cathode under high working voltage. The GDY‐coated LNMO cathode obviously alleviates the electrolyte degradation, achieves high Coulombic efficiency and reliability. Due to atomic‐level selectivity and chemical trapping of HF by GDY, it effectively suppresses the dissolution of Mn, Ni elements. These results highlight the unparalleled advantages of GDY in the formation of high stable interfaces and protection of high‐energy‐density electrodes.

Improved Electrochemical Performance of Spinel LiNi0.5Mn1.5O4 Cathode Materials with a Dual Structure Triggered by LiF at Low Calcination Temperature

“…Surface coating is the most common and simple method to hinder the interfacial reaction between the LNMO cathode and electrolyte, prevent the TMs’ dissolution, and improve the cycling performance of LNMO. By coating the surface of LNMO particles with a thin layer of metal oxides (Al 2 O 3 , ZnO, TiO 2 , RuO 2 ), − metal fluoride (AlF 3 ), phosphate (YPO 4 , Li 3 PO 4 ), , carbon materials (graphene), and conductive organic material (polyaniline), it can effectively prevent direct contact between the cathode and electrolyte, avoid the corrosion of harmful substances such as HF, and therefore improve the cycling stability of LNMO. However, these surface coatings, even if some of them are Li + conductors (LATP), have difficulty forming a concrete coating on the surface of LNMO or reacting with the decomposition products of electrolytes during the cycling periods.…”

Controlled Growth of 3D Interpenetrated Networks by NiCo2O4 and Graphdiyne for High-Performance Supercapacitor

“…The coating of GDY is carried out according to our previous report . Briefly, the NiCo 2 O 4 - W , NiCo 2 O 4 - D , and NiCo 2 O 4 - S on the nickel foam are sealed in glass bottles containing HEB (hexakisethynyl benzene) (5 mL, 0.5 mg mL –1 ), diethyl ether (20 mL), pyridine (100 μL), and copper acetate (2 mg) and kept in the dark for 2 days.…”

Advances in modification methods and the future prospects of high-voltage spinel LiNi0.5Mn1.5O4— a review

“…Thereby, the electrochemical performance of LNMO is improved. 114 3.4.7 The "self-coating" method. Recently, some scholars have released a new special method to "coat" LNMO, that is, heat treatment of LNMO itself without introducing other substances and obtained a LNMO surface layer with two phases.…”