POWER STORAGE DEVICE

• Main Authors: WATANABE HIDETO, KODAMA MITSUHIRO, KANEMOTO MANABU
• Format: Patent
• Language: English; Japanese
• Published: 08.11.2018
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

PROBLEM TO BE SOLVED: To provide a power storage device arranged so that the decrease in utilization rate after a charging action has been continued for a long time at a high temperature can be suppressed.SOLUTION: A power storage device comprises: an electrode group having a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes; and an electrolyte solution containing sodium ions. The percentage of a volume of the electrolyte solution to a spatial volume in the electrode group is 75% or more. An electric capacity (Y) per unit area in any one of the positive and negative electrodes is 45 mAh/cm2 or less. The nickel hydrogen storage battery has a nickel compound as an active material of the positive electrode, and uses a hydrogen-occluding alloy as an active material of the negative electrode.SELECTED DRAWING: None 【課題】高温で長時間充電を続けたあとに利用率が低下することが抑制された蓄電素子を提供する。【解決手段】正極と、負極と、正極及び負極の間に配置されたセパレータとを有する電極群と、ナトリウムイオンを含有する電解液とを含み、電極群内の空間体積に対する、電解液の体積の割合は、７５％以上である、蓄電素子。前記正極及び前記負極のいずれか一方における単位面積あたりの電気容量（Ｙ）は、４５ｍＡｈ／ｃｍ２以下である、ニッケル化合物を正極の活物質として有し、水素吸蔵合金を負極の活物質として利用するニッケル水素蓄電池。【選択図】なし