Chinese battery giant CATL is in talks to acquire a controlling stake in Nio Power, the power unit of EV maker Nio.Nio Power currently operates over 3,000 battery-swapping stations in China.As part of a strategic partnership signed last month, CATL will invest a maximum of RMB 2.5 billion in Nio Power.CATL aims to diversify beyond battery making and has recently partnered with Sinopec to build 10,000 battery-swapping stations.