Enhanced Cyclic Stability of Spinel LiMn₂O₄ for Lithium‐Ion Batteries by Surface Coating with WO₃

Abstract

WO3‐modified LiMn2O4 was synthesized by using a simple wet‐chemical process followed by solid‐state reaction. After surface coating modification, a high discharge capacity of 125.6 mAh g−1 with retention of 94.8 % was obtained at a current density of 1 C between 3.3 and 4.3 V after 100 cycles. The XRD patterns showed that the crystal structure of LiMn2O4 was not altered by coating WO3 and the HRTEM image showed the solution method had been used to prepare the WO3‐coated LiMn2O4 successfully. From electrochemical impedance spectroscopy and cyclic voltammetry analysis, the WO3 coating was shown to decrease the charge‐transfer resistance and avoid the disproportionation reaction of manganese into the electrolyte solution. The WO3 surface coating is a promising approach to improve the cyclic stability of lithium manganese oxide.

A Comparative Review of Metal Oxide Surface Coatings on Three Families of Cathode Materials for Lithium Ion Batteries

“…In a study by Feng et al [71] tungsten(III) oxide (WO 3 ) was coated onto LiMn 2 O 4 cathode material in order to evaluate its protective effects against Mn dissolution into the electrolyte. The best performing coated sample delivered a capacity retention of 89.4% at 1 C when compared to 75.1% from the bare LiMn 2 O 4 at room temperature after 50 cycles [71]. Furthermore, the WO 3 coating showed better performance even at higher rates and elevated temperatures as observed in Table 3.…”

Free-standing ternary metallic sulphides/Ni/C-nanofiber anodes for high-performance lithium-ion capacitors

“…The position of oxidation peak at 1.3 V is reversible in the following cycles. Additionally, in the subsequent cycles, the CV curves tend to overlap, representing well reversibility of the electrochemical reactions for TMSs/Ni/C-NFs film in the charge/discharge process [41] . The representative discharge-charge curves of TMSs/Ni/C-NFs film electrode for the 1st, 2nd, 10th, 50th and 80th cycles at a low current rate of 100 mA g −1 are displayed in Fig.…”

Review of the Scalable Core–Shell Synthesis Methods: The Improvements of Li‐Ion Battery Electrochemistry and Cycling Stability

“…However, WO 3 will behave as an insulator, which is harmful to cycling if it excessively covers LiMn 2 O 4 . EIS was conducted on both the uncoated and coated LiMn 2 O 4 at the 1st and 100th cycle to [286] Copyright 2016, Wiley-VCH. e) Schematic illustration of LNMO@SiO 2 core-shell synthesis via the ball-milling process.…”