BEIJING, July 21 (Reuters) - China"s top electric vehicle (EV) battery maker CATL (300750.SZ) said on Wednesday it had sued smaller rival China Lithium Battery Technology Co (CALB) for alleged intellectual property violations. CATL, which supplies Tesla Inc (TSLA.O) and Volkswagen AG (VOWG_p.DE), said in a statement the lawsuit related to batteries made by CALB using its new technologies that have been installed on tens of thousands of vehicles. CATL filed the lawsuit in the southeastern city of Fuzhou, near its Ningde headquarters. CALB, which supplies GAC (601238.SS), said in a statement on its Wechat account that it focused on independent research and technology advancement. The batteries it supplies to customers have passed assessments to make sure they do not violate others" intellectual property rights, it added. Batteries are crucial components of EVs and Chinese companies are expanding production globally. According to sales rankings by the China Automotive Battery Innovation Alliance, CATL was China"s top EV battery maker in the first half of this year, followed by BYD (002594.SZ) and LG Energy Solution. CALB was No. 4, with a much smaller market share than CATL.