Highly Conductive Two-Dimensional Metal–Organic Frameworks for Resilient Lithium Storage with Superb Rate Capability

Abstract

Redox-active organic cathode materials have drawn growing attention because of the broad availability of raw materials, eco-friendliness, scalable production, and diverse structural flexibility. However, organic materials commonly suffer from fragile stability in organic solvents, poor electrochemical stability in charge/discharge processes, and insufficient electrical conductivity. To address these issues, using Cu(II) salt and benzenehexathiolate (BHT) as the precursors, we synthesized a robust and redox-active 2D metal−organic framework (MOF), [Cu 3 (C 6 S 6 )] n , namely, Cu-BHT. The Cu-BHT MOFs have a highly conjugated structure, affording a high electronic conductivity of 231 S cm −1 , which could further be increased upon lithiation in lithium-ion battery (LIB) applications. A reversible four-electron reaction reveals the Li storage mechanism of the Cu-BHT for a theoretical capacity of 236 mAh g −1 . The as-prepared Cu-BHT cathode delivers an excellent reversible capacity of 175 mAh g −1 with ultralow capacity deterioration (0.048% per cycle) upon 500 cycles at a high current density of 300 mA g −1 . Therefore, we believe this work would provide a practical strategy for the development of highpower energy storage materials.

Effects of Various Elements Doping on LiNi0.6Co0.2Mn0.2O2 Layered Materials for Lithium‐Ion Batteries

“…This effective improvement in characteristics can be attributed to movement of Cu 2þ ions to the electrode surface and formation of solid solution protective layer, thereby preventing the corrosion of the active substance by the electrolyte. [38][39][40] The lower Li þ /Ni 2þ mixing can also improve the cycle properties.…”

Two-dimensional conjugated metal–organic frameworks (2D c-MOFs): chemistry and function for MOFtronics

“…25a). 35,36,87,88,202 As a typical example, Wada et al reported the utilization of Ni 3 (HIB) 2 2D c-MOFs in Li-ion batteries in 2018. 36 As a cathode material, Ni 3 (HIB) 2 delivered a high specific capacity of 155 mA h g À1 in a 1 M LiPF 6 electrolyte (Fig.…”

Recent Progress and Prospects of Layered Cathode Materials for Potassium‐ion Batteries

“…2D COFs/MOFs are also layered materials with robust frameworks, high crystallinity, and porosity. [127,128] Different from traditional organic electrode materials, these frameworks exhibit unique features including insolubility in electrolyte and open channels for the facilitated ions transportation. Therefore, COFs/MOFs have been widely applied in rechargeable batteries.…”

“…Therefore, COFs/MOFs have been widely applied in rechargeable batteries. [124][125][126][127][128][129] However, as nascent materials, the applications of 2D COFs/MOFs as cathode materials for PIBs are scarce. [130,133,134] Their large channels are both challenges and opportunities for large K + ions, while a wide range of novel compounds can be expected due to the high designability of COFs/MOFs.…”