Secondary battery, battery pack, vehicle, and stationary power supply
摘要
說明書
Note that each of the primary particle size and the secondary particle size means a particle size with which a volume integrated value becomes 50% in a particle size distribution obtained by a laser diffraction particle size distribution measuring apparatus. As the laser diffraction particle size distribution measuring apparatus, Shimadzu SALD-300 is used, for example. For measurement, luminous intensity distribution is measured 64 times at intervals of 2 seconds. As a sample used when performing the particle size distribution measurement, a dispersion obtained by diluting the negative electrode active material particles by N-methyl-2-pyrrolidone such that the concentration becomes 0.1 mass % to 1 mass % is used. Alternatively, a measurement sample obtained by dispersing 0.1 g of a negative electrode active material in 1 to 2 ml of distilled water containing a surfactant is used.
The specific surface area of the negative electrode active material in the BET method by nitrogen (N2) adsorption falls within the range of, for example, 3 m2/g to 200 m2/g. If the specific surface area of the negative electrode active material falls within this range, the affinity between the negative electrode and the aqueous electrolyte can be made higher. The specific surface area can be obtained by, for example, the same method as that for the specific surface area of the negative electrode active material-containing layer.
The negative electrode active material-containing layer may contain a conductive agent, a binder, and the like in addition to the negative electrode active material.
