An operando X-ray diffraction study of chloroaluminate anion-graphite intercalation in aluminum batteries

Significance Operando X-ray diffraction experiments are performed to investigate chloroaluminate anion intercalation into a graphite positive electrode during electrochemical charging and discharging of rechargeable aluminum batteries in situ. The results revealed surprisingly ordered anion intercalation staging behavior in graphite despite the large anion size and the remarkably stable graphite structure upon repeated intercalation and deintercalation by the large anions. The basic understanding will guide the design and development of new battery materials and new batteries.