Porous CoF₂ Spheres Synthesized by a One‐Pot Solvothermal Method as High Capacity Cathode Materials for Lithium‐Ion Batteries

Abstract

Up to now, there are rare reports of CoF2 spheres used as high capacity cathode materials. Herein, porous CoF2 spheres were synthesized and studied as cathode materials for LIBs. The porous CoF2 spheres were synthesized by a facile one‐pot solvothermal method using a safe and inexpensive ammonium fluoride as the fluorine sources. The nature of the synthesis can avoid using corrosive fluorine sources and additional high‐temperature thermal treatment. The structure, morphologies and electrochemical performance of the samples obtained at different reaction times and solvothermal temperatures were investigated. The results show that the CoF2 spheres obtained at 200 °C for 20 h show better electrochemical performances, including a high initial discharge capacity, good capacity retention and high Coulombic efficiency. It can deliver a high initial discharge capacity of 537.8 mA•h•g−1 and keep 127.4 mA•h•g−1 after 30 cycles used as cathode materials for lithium‐ion batteries. The good electrochemical performances may be attributed to good crystallinity, porous structure and relatively intermediate sphere size.

Novel Synthesis of Anhydrous and Hydroxylated CuF2 Nanoparticles and Their Potential for Lithium Ion Batteries

“…A second plateau around 4.2 V is caused by another side reaction. This plateau at high potential could be due to the decomposition of the electrolyte, due to the catalytic power of metal fluorides, as it has been already observed in the literature . Almost no capacity is released during the second discharge of the CuF 2 ‐4 material, which could be due to the total dissolution of the converted metallic copper.…”

3D Honeycomb Architecture Enables a High‐Rate and Long‐Life Iron (III) Fluoride–Lithium Battery

“…However, most of the previously reported metal fluoride particles did not yield uniform particles with a mean size of less than 100 nm and with controlled morphology . Hence, rate capability and cycle life were limited (only 100 cycles achievable in total, small active mass loading of ≈1.0 mg cm −2 or no indication of mass loadings) and these reports were far‐off from the standard of a practical application.…”

Progresses in Manufacturing Techniques of Lithium‐Ion Battery Separators in China

“…Since the first introduction of the rechargeable lithium‐ion batteries (LIBs) in 1991 by Sony, the LIBs with high energy density and long cycle life are rapidly becoming the preferred choice for electric vehicles (EVs), powering portable electronic devices and energy storage systems . Separator is one of the four key components in LIBs that prevents electronic contact between the positive and negative electrodes and allows rapid ionic transportation through its porous structure.…”