Lithium ion cells have been constructed with a stabilised lithium metal powder incorporated in the anode. The powder can be used to compensate for the irreversible capacity of the anode, allowing anode materials with large reversible and irreversible capacities to be used. The powder also enables high capacity, non-lithiated cathode materials to be used in lithium ion cells. The stabilised lithium metal powder is safe to use in dry air, provided reasonable safety precautions are followed.