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

A large-capacity lithium-ion battery of 1 kWh (300 Ah) class was fabricated by using LiCoO2 and natural graphite as the cathode and anode materials, respectively, and LiPF6 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 LiBF4 as the electrolyte [5,6]. These improvements were achieved by changing the following factors: (i) use of LiPF6 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.