SES, a battery startup supported by General Motors, Hyundai, and Honda, has entered into a joint development agreement (JDA) with one of its major investors to create prototype lithium-metal batteries labeled as B-Sample. This move aims to promote the adoption of this emerging technology in electric vehicles. Chief Executive Hu Qichao, declaring the agreement the first of its kind in the industry on Wednesday, didn’t disclose the carmaker’s name but mentioned that a similar deal with another backer is imminent. The B-Sample is the second-level prototype in the automotive industry, featuring full specifications and can be installed into test vehicles for further validation, typically taking one to two years. Last May, the Boston-headquartered company announced its intention to enter the series production process after completing the validation of C/D-sample which may last another two years. Lithium-metal batteries, which lack the carbon materials used in existing lithium-ion batteries and have pure metal lithium in the anode, theoretically offer longer driving ranges and more cabin space. [TechNode reporting]