Synergistic effect of sulfur on electrochemical performances of carbon‐coated vanadium pentoxide cathode materials with polyvinyl alcohol as carbon source for lithium‐ion batteries

Abstract

Summary Vanadium pentoxide (V2O5) is a common cathode material for lithium‐ion battery, but its low electronic and ionic conductivity seriously affect its electrochemical performances. In this paper, a type of carbon‐coated V2O5 and S composite cathode material with PVA as the carbon source is utilized to lithium‐ion batteries. X‐ray diffraction and Raman test results illustrate that sulfur can make the V2O5 lose part of oxygen atoms and become nonstoichiometric vanadium oxide (V2O5‐x). Electrochemical test results show that sulfur can provide a considerable proportion of the specific capacity of the whole cathode. This illustrates that the synergistic effect of sulfur can optimize the structure of vanadium pentoxide in order to increase more electron transfer channels, and at the same time, it also can provide additional specific capacity for the whole cathode. When the ratio of V2O5 and sulfur is 1:3, the discharge specific capacity can reach 923.02, 688.37, and 592.70 mAh g−1 at 80, 160, and 320‐mA g−1 current density, respectively, and after 100 times charge and discharge cycles at 320‐mA g−1 current density, the capacity retention rate can achieve to more than 60%.

Influence of TiO 2 /TiC composite materials with different crystal structures on the electrochemical properties as sulfur‐loaded matrix for lithium‐sulfur batteries

“…Carbon, metal compound and conductive polymer material are the most commonly matrix material owing to ideal conductivity, pore structure and sulfur adsorption strength. [7][8][9][10][11][12][13][14][15][16] Among these, TiO 2 is regarded as an ideal sulfur-loaded matrix material and is believed that TiO 2 /S composite electrode can effectively inhibit the shuttle effect of polysulfides as a result of the strong adsorption between Ti-O structure and sulfur, thus improving sulfur utilization and cycle life for lithium-sulfur batteries. As known to all, TiO 2 has a variety of microstructures, including rutile and anatase.…”

High electrochemical performance small grain size vanadium pentoxide prepared by hydrothermal method and as high proportion sulfur supported matrix materials for lithium‐sulfur batteries

“…In our previous research, it displayed that vanadium pentoxide is an ideal sulfur-loaded matrix material for high electrochemical performance lithium-sulfur batteries. 26 In this experiment, a small grain size vanadium pentoxide prepared at 140 C hydrothermal temperature which has the most excellent electrochemical properties is used as sulfur-loaded matrix material for lithium-sulfur and the effects of different sulfur loading ratios on the electrochemical properties are investigated. Figure 5 shows SEM images of vanadium pentoxide prepared at 140 C hydrothermal temperature after sulfur loading at different mass ratio.…”

A novel flower‐like metal‐based oxides with cross‐linked networks for rapid lithium‐ion storage

“…Along with the improvement of economy and growing requirements of people, the developments of highperformance nonrenewable energy resources are more and more urgent and eager, such as alkaline-ion batteries, fuel cell, and supercapacitors. [1][2][3][4] Among them, lithium-ion batteries (LIBs) still occupy the dominant energy conversion and storage positions all over the world on account of the wide voltage windows, ultrahigh power density, and long cyclic life, which are widely applied for portable electronic units and mobile communication equipments. 5,6 Nevertheless, the traditional LIBs cannot satisfy people's growing requirements on account of the fast capacity decay after repeated charging and discharging.…”