Lithium-ion secondary battery

摘要

A lithium-ion secondary battery (100) includes a positive electrode mixture layer (223) coated on a positive electrode current collector (221), a negative electrode mixture layer (243) coated on a negative electrode current collector (241), and an electrolyte solution containing lithium ions at a predetermined concentration. The number of lithium ions X in the electrolyte solution impregnated per 1 cm3 of the positive electrode mixture layer (223) and the number of lithium ions Y in the electrolyte solution impregnated per 1 cm3 of the negative electrode mixture layer (243) are both 3.75×1019 or greater.

主权项

1. A power supply system comprising:
a secondary battery; and a battery control unit electrically connected to the secondary battery and configured to determine an upper limit value W of the amount of consumed electric charge per unit time during discharge of the secondary battery, wherein: the secondary battery comprises: a positive electrode current collector; a positive electrode mixture layer, coated on the positive electrode current collector, and containing at least a positive electrode active material and a conductive material; a negative electrode current collector; a negative electrode mixture layer, coated on the negative electrode current collector, and containing at least a negative electrode active material; and an electrolyte solution containing lithium ions at a predetermined concentration, wherein: the positive electrode mixture layer has pores for impregnating the electrolyte solution; the negative electrode mixture layer has pores for impregnating the electrolyte solution; the number of lithium ions X0 in the electrolyte solution impregnated in the positive electrode mixture layer is obtained by the following equation:
X0=(the volumetric capacity Vb (cm3) of the pores in the positive electrode mixture layer)×(the lithium ion concentration L (mol/L) of the electrolyte solution)×Avogadro's number (NA)×1/1000; the number of lithium ions Y0 in the electrolyte solution impregnated in the negative electrode mixture layer is obtained by the following equation:
Y0=(the volumetric capacity Vd (cm3) of the pores in the negative electrode mixture layer)×(the lithium ion concentration L (mol/L) of the electrolyte solution)×Avogadro's number (NA)×1/1000; the upper limit value W of the amount of consumed electric charge is determined so as to correspond to a charge-discharge rate at which the number of lithium ions X0 or the number of lithium ions Y0 is consumed in one time of charging or discharging; and the battery control unit controls charging or discharging under a condition in which the number of lithium ions X0 and the number of lithium ions Y0 are both equal to or greater than the number of consumed lithium ions Z in one time of charging or discharging.