Although sales of electric and hybrid vehicles have struggled, automakers are charging ahead to bring new battery-powered vehicles to market. Several car companies have focused on electric vehicles at the International CES consumer trade show here, including General Motors, which on Wednesday introduced the production version of its Chevrolet Bolt. G.M.’s chief executive, Mary T. Barra, said the Bolt was a big step forward in the electrification of vehicles because of its price and ability to travel 200 miles on a fully charged battery. “This is truly the first EV that cracks the code because of long range at an affordable price,” Ms. Barra said in a keynote speech at the show. The Bolt, which will go on sale this year, will carry a sticker price of $30,000, including government incentives that total about $7,500.