One researcher I spoke with at the time suggested that sodium-ion batteries might not compete directly with lithium-ion batteries but could instead find specialized uses where the chemistry made sense. There’s a great BBC story from last week that profiled efforts to put sodium-ion batteries in electric scooters. Sodium-ion batteries are also seeing significant progress in stationary energy storage installations, including some on the grid. The Baochi Energy Storage Station that just opened in Yunnan province, China, is a hybrid system that uses both lithium-ion and sodium-ion batteries and has a capacity of 400 megawatt-hours. The Chinese battery giant CATL announced earlier this year that it plans to produce sodium-ion batteries for heavy-duty trucks under the brand name Naxtra Battery.