前田 光治

We found that an AAA-type battery (min. 750 mAh) pressurized with Ar or N₂ at pressures of up to 5 MPa exhibited a significant durability enhancement even under high-current conditions.

<title>Abstract</title> A nickel-metal hydride (Ni–MH) prototype battery completely immersed in an aqueous electrolyte solution of KOH under high pressure was fabricated to examine the effects of high pressure on the quality of Ni–MH batteries. The small battery cell comprised positive and negative electrode materials, as used in electric vehicles, and an Ag/AgO reference electrode. The electric capacity of the Ni–MH battery was measured at different temperatures and pressures with small currents and charge/discharge voltages of 1.6 – 1.0 V. High pressures were found to clearly and effectively enhance the electric capacity of the Ni–MH battery at larger currents. The considerable effect of high pressure on the Ni–MH battery was elucidated by the change in internal resistance during the charge/discharge cycle life experiment, indicating that the voltage of the positive electrode did not appreciably change at a high pressure compared to that of the negative electrode. Moreover, the use of large currents in rapid charge/discharge cycle tests at high pressures of up to 30 MPa resulted in charge/discharge cycles that were five times faster and a quick recovery of capacity was achieved in the 0.5 – 2.1 V range.

海洋資源の大半は電解質であり，主としてイオンとして溶解状態にある．その70 wt％以上は塩化ナトリウムであるが，塩化ナトリウム以外にも多くの電解質資源が溶解している．ここでは，海水中の電解質の回収分別操作の開発を目指して，海水中に含まれる主な電解質に適用できる電解質溶液モデルを検討した．電解質溶液モデルは，高濃度多成分系にも適用できる電解質NRTL（Non-Random Two Liquid）モデルである．海水中に溶解している主な電解質に関する2成分系（水＋単1電解質）の溶解度データを電解質溶液モデルで整理し，塩の溶解度積パラメータを求めた．そして，いくつかの3成分系（水＋2成分電解質）の溶解度データを電解質溶液モデルで検討した．