Effect of Acetylene Black on the Electronic Conductivity of a Cathode Material Based on the Li1.3V3O8 Vanadium Bronze
摘要
The lithium–vanadium Li1 + xV3O8 bronze is being investigated as a promising cathode material for lithium and lithium-ion current sources with a liquid electrolyte. In the previous work, we synthesized the lithium–vanadium Li1.3V3O8 bronze from a melt of the initial components and achieved a grain size of about 5 μm in the synthesized material and a room-temperature electrical conductivity of ~10–3 S/cm, which is several orders of magnitude higher than the conductivity of commercial cathode materials. In this paper, we investigate the effect of a conductive acetylene black additive on the electrical resistance of cathodes with Li1.3V3O8 at room and elevated temperatures for liquid electrolyte power sources and for medium-temperature (up to 300°C) all-solid-state batteries. Isothermal holdings performed at various temperatures demonstrate that lithium–vanadium Li1.3V3O8 oxide powders and acetylene black do not interact with each other up to a temperature of 200°C and can be used to create a cathode for a medium-temperature current source. The introduction of a fine acetylene black conductive additive into Li1.3V3O8 is found to increase the electronic conductivity of the cathode mass (to 7.8 × 10–2 S/cm at 5 wt % C and 25°C) and to decrease the contact resistance at the electrode/metallic substrate interface.