Organic electrode for non-aqueous potassium-ion batteries

Potassium-ion (K-ion) batteries can be an attractive alternative for grid-scale energy storage due to the abundance of K resources. For the first time, we designed and fabricated a non-aqueous K-ion battery (KIB) by employing 3,4,9,10-perylene-tetracarboxylicacid-dianhydride (PTCDA) as the cathode. The PTCDA electrode exhibits a high capacity of 131 mA h g(-1) in the potential range of 1.5-3.5 V vs. K/K+, which corresponds to the insertion of two K ions per PTCDA molecule. The PTCDA cathode also shows great cycling performance, with a capacity retention of 66.1% over 200 cycles. Furthermore, K(11)PTCDA can be obtained when discharging PTCDA to 0.01 V vs. K/K+, which delivers a high capacity of 753 mA h g(-1). The excellent electrochemical performance makes PTCDA a promising organic electrode based on K-ion chemistry for grid-scale energy storage. Published by Elsevier Ltd.