Si1-B-x(x) thin films of 0.071 <= x <= 0.950 have been synthesized using combinational sputtering. All Si1-B-x(x) film compositions had a highly amorphous structure consisting of amorphous Si and B phases, as characterized by X-ray diffraction. In Li cells, it was found that all of the Si is active and the B is inactive with lithium. Otherwise, the Si1-B-x(x) films have similar characteristics as pure Si film electrodes in Li cells, except with reduced capacity due to the added B. However, shifts in the voltage curves appear when the B content is increased that may be induced by stress-voltage coupling between the active Si and the inactive B phases. (C) The Author(s) 2015. Published by ECS.