The electrochemistry of KC8 in a lithium-containing ethylene carbonate-dimethylcarbonate electrolyte has been studied. The results show that upon oxidation KC8 irreversibly releases potassium ions and that during the following cathodic cycle, the residual graphite intercalates lithium reversibly and with fast rate up to a LiC6 composition : The results also show that a KC8 electrode can be used in lithium-ion cells in combination with partially lithiated or even with lithium-free cathodes. The maximum capacities (referred to the anode) that may be achieved are 372 and 279 mAh g(-1), respectively.