Secondary battery, battery pack, vehicle, and stationary power supply
摘要
說明書
Whether the solid electrolyte layer contains an electrolyte salt can be confirmed, for example, based on an alkali metal ion distribution obtained by energy dispersive X-ray spectrometry (EDX) for a section of the solid electrolyte layer. That is, if the solid electrolyte layer is made of a material that does not contain an electrolyte salt, the alkali metal ions remain in the surface layer of the polymeric material in the solid electrolyte layer, and therefore, rarely exist inside the solid electrolyte layer. Hence, a concentration gradient representing that the concentration of alkali metal ions is high in the surface layer of the solid electrolyte layer, and the concentration of alkali metal ions is low inside the solid electrolyte layer can be observed. On the other hand, if the solid electrolyte layer is made of a material containing an electrolyte salt, it can be confirmed that the alkali metal ions evenly exist inside the solid electrolyte layer as well.
On the other hand, if the electrolyte salt contained in the solid electrolyte layer and the electrolyte salt contained in the aqueous electrolyte are of different types, it can be found based on the difference of existing ions that the solid electrolyte layer contains an electrolyte salt different from that in the aqueous electrolyte. For example, when lithium chloride (LiCl) is used as the aqueous electrolyte, and LiTFSI (lithium bis(fluorosulfonyl)imide) is used as the solid electrolyte layer, the existence of (fluorosulfonyl)imide ions can be confirmed in the solid electrolyte layer. On the other hand, in the aqueous electrolyte on the negative electrode side, the existence of the (f luorosulfonyl)imide ions cannot be confirmed, or the (fluorosulfonyl)imide ions exist at a very low concentration.
