BioSolar Inc. has filed a patent application for a process to protect its high-power batteries for use in power tools and hybrid electric vehicles. The Santa Clarita company has applied its silicon additive technology to materials that can reduce the cost of lithium-ion battery engineering and manufacturing, it said in a release. Chief Executive David Lee said that filing the patent application brings the company one step closer to the commercialization of its silicon additive technology. “As we move forward, it is critical that we control future licensing efforts that may one day represent a significant source of revenue,” Lee said in a statement. “We are pleased to file this patent and continue focusing on the evaluation of the technology.” Shares of BioSolar (BSRC) closed Tuesday up a fraction of a cent, or more than 2 percent, to just less than half a cent on the over-the-counter market.