context: Small molecules. Perylenetetracarboxylic dianhydride (PTCDA 9) was relatively widely studied in potassium batteries. It was first proposed for K-based cells by Hu et al., who tested it with a carbonate-based electrolyte. The material delivered a Qm of 130 mA h g−1 at 10 mA g−1 with an average discharge potential of 2.4 V, while 66% of that capacity was retained after 200 cycles. At 500 mA g−1, the capacity dropped to 73 mA h g−1.
answer: carbonate-based