This one article mentions a novel battery based on polymer electron transfer process. It doesn't seem to contain any Lithium. The claimed energy density is 590 Wh/kg which is much higher than Li-ion. Unfortunately I was not able to find a full text. Does anyone heard in the past about such type of chemistry? Could there be an all-polymer battery? A High Energy Rechargeable Battery Based on a One-Step Successive Two-Electron Transfer Process