The electrochemical properties of two anthraquinone-based polyimides as cathodes for lithium secondary batteries were investigated. These two polyimides delivered capacities of 230 and 210 mA h g(-1). The cyclability was enhanced significantly by increasing the electrolyte concentration, and specific capacities as high as 160 and 173 mA h g-1 were obtained after 200 cycles when using concentrated electrolytes.