Different cathode and anode materials can be used for these cells which allows for designing a wide range of differently behaving cells. There are high energy density types, e.g. LiCo02, as well as high power density types, e.g. Li-titanate, available. Electric vehicles possess batteries and can deliver services by delivering power back to the grid, the process known as vehicle to grid (V2G).This bidirectional energy flow can be used for peak-shaving, frequency control, emergency back-up.