Development of 1 kWh (300 Ah) class lithium-ion battery

Abstract A large-capacity lithium-ion battery of 1 kWh (300 Ah) class was fabricated by using LiCoO 2 and natural graphite as the cathode and anode materials, respectively, and LiPF 6 as the electrolyte to develop industrially usable batteries for energy source. Our battery delivered an energy density of 60 Wh/kg (133 Wh/l) with weight and volume of a container included with a cycle life of 245 cycles, which was longer compared with that of our former battery using LiBF 4 as the electrolyte [5,6]. These improvements were achieved by changing the following factors: (i) use of LiPF 6 as the electrolyte; (ii) optimizing the mixing ratio of the solvent (EC/DEC); (iii) employing a plate spring for the buffer of electrode expansion and shrinkage; (iv) minimizing residual moisture.