抄録
The interfacial reactions that contributed to the gas formation between carbon conductive agents and the electrolyte at the positive electrode in high-voltage batteries, potentials over 4.5 V, have been investigated. The amount of gas generated was quantified for various conductive agents: acetylene black (AB), furnace black (FB), specially customized AB, and graphite (GR). The experiments revealed that in the high-voltage system, the specific gas evolution was induced by both the cathode active material and the conductive agent. The high-voltage properties of the carbon conductive agents, such as the anion intercalation and self-discharging properties, were evaluated for each carbon electrode. The results implied the existence of a local battery composed of the conductive agent and LNi0.5Mn1.5O4. This redox couple appears to play a key role in the gas evolution, which was sensitive to crystallinity, surface area and metallic impurities of conductive agents.
