HYBRID ELECTRIC VEHICLE, AND LITHIUM ION SECONDARY BATTERY SELECTION METHOD FOR HYBRID ELECTRIC VEHICLE

摘要

A hybrid electric vehicle is provided which utilizes a wider usage range of a lithium ion secondary battery relative to the SOC so as to accommodate the system side of a vehicle having a fuel economy-oriented system. In this hybrid electric vehicle, on the system side of the vehicle, the value of the ratio (W_out/W_in) of the maximum output request W_out to the maximum input request W_in to the lithium-ion secondary battery (9A) is set to less than 1.5. In the lithium-ion secondary battery (9A) that is installed, the maximum input value P_in, the maximum output value P_out, the maximum input request W_in and the maximum output request W_out satisfy (expression 1) below, the positive electrode active material layer contains 80 mass% or more of a ternary material (Li(Ni-Mn-Co)O₂) in which a part of the cobalt of lithium cobaltate is replaced with nickel and manganese, and the negative electrode active substance layer contains 80 mass% or more of graphite.(P_in + P_out) / 3 (W_in + W_out) (formula 1)