High-capacity polymer electrodes for potassium batteries

We synthesized and investigated a series of six promising polymeric electrode materials, which incorporate multiple redox-active groups enabling high specific discharge capacity and energy density in potassium half-cells. All investigated polymers showed a discharge capacity exceeding 200 mA h g(-1) and no capacity fading after several hundred charge-discharge cycles. The best-performing material P1 delivered a discharge capacity of 422 mA h g(-1) and record-high energy density of similar to 696 W h kg(-1) at 0.5 A g(-1) in combination with a specific power of >20 000 W kg(-1) reached at a specific current of 12 A g(-1). The obtained results place P1 among the best electrode materials reported so far for potassium-ion batteries.