Graphene Nanoplatelet-Polysulfone Composite Cathodes for High-Power Aluminum Rechargeable Batteries

抄録

Low-cost graphene nanoplatelet-polysulfone composite cathodes for a rechargeable aluminum battery with a Lewis acidic AlCl₃–1-ethyl-3-methylimidazolioum chloride ([C₂mim]Cl) ionic liquid are prepared by a standard slurry-coating method for the composite electrode, and conductive additives such as acetylene black (AB), ketjen black (KB), and vapor grown carbon fiber (VGCF) are explored in order to improve the cathode performance. All the cathodes show reversible electrode reactions related to the intercalation reaction of [AlCl₄]⁻ into the graphene nanoplatelets. The cathodes achieve a discharge capacity of ca. 70–80 mAh g⁻¹ at 1000 mA g⁻¹. However, the rate capability and the capacity retention rate strongly depend on the conductive additive species. The best cathode performance is obtained when the additive is an equal mixture of VGCF and KB. The specific capacity is ca. 55 mAh g⁻¹ at 10000 mA g⁻¹. The retention rate based on the capacity observed at 1000 mA g⁻¹ exceeds 65%. A Ragone plot constructed from the data shown in this article suggests that an Al rechargeable battery with a VGCF-KB added graphene nanoplatelet-polysulfone composite cathode has great potential as a future high-power density rechargeable battery.