China’s electric vehicle (EV) battery makers saw their combined net profit in the first half of the year nearly double that of the country’s major carmakers, widening the profitability gap amid weakening domestic demand for EVs.Seven major battery manufacturers, including Contemporary Amperex Technology Limited (CATL), recorded a net profit of over 50 billion yuan (US$7.4 billion) during the January-June period, up 49 per cent year on year, according to the companies’ exchange filings.However, China’s 11 major EV makers, from BYD to Great Wall Motor, saw their combined interim net profit shrink by 19 per cent over the same period to…