Secondary battery, battery pack, vehicle, and stationary power supply
摘要
說明書
In addition, the pH of the aqueous electrolyte on the negative electrode side and that on the positive electrode side are preferably different after the initial charge. In the secondary battery after the initial charge, the pH of the aqueous electrolyte on the negative electrode side is preferably 3 or more, more preferably 5 or more, and much more preferably 7 or more. In the secondary battery after the initial charge, the pH of the aqueous electrolyte on the positive electrode side preferably falls within the range of 0 to 7, and more preferably falls within the range of 0 to 6.
The pHs of the aqueous electrolyte on the negative electrode side and the positive electrode side can be obtained by, for example, disassembling the secondary battery and measuring the pH of the aqueous electrolyte existing between the separator and the negative electrode and the pH of the aqueous electrolyte existing between the separator and the positive electrode.
As the aqueous solvent, a solution containing water can be used. Here the solution containing water may be pure water or a solvent mixture of water and an organic solvent.
The aqueous electrolyte may be a gel electrolyte. The gel electrolyte is prepared by mixing the above-described liquid aqueous electrolyte and a high-molecular compound and compounding them. As the high-molecular compound, for example, polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO), and the like can be used.
