Electricity systems require energy storage on all time scales to accommodate the variations in output of solar and wind power when those sources of electricity constitute most, or all, of the generation on the system. This paper builds on recent research into nickel-iron battery-electrolysers or “battolysers” as both short-term and long-term energy storage. For short-term cycling as a battery, the internal resistances and time constants have been measured, including the component values of resistors and capacitors in equivalent circuits. The dependence of these values on state-of-charge and temperature have also been measured. The results confirm that a nickel-iron cell can hold 25% more than its nominal charge. However, this increased capacity disappears at temperatures of 60°C and may be dissipated quickly by self-discharge. When operating as an electrolyser for long-term energy storage, the experiments have established the importance of a separation gap between each electrode and the membrane for gas evolution and established the optimum size of this gap as approximately 1.25 mm. The nickel-iron cell has acceptable performance as an electrolyser for Power-to-X energy conversion but its large internal resistance limits voltage efficiency to 75% at 5-h charge and discharge rate, with or without a bubble separation membrane.

电力系统需要在所有时间范围内进行能量存储，以适应当太阳能构成系统中大部分或全部发电量时太阳能和风能输出的变化。本文基于对镍铁电池电解槽或“ battolysers”作为短期和长期储能的最新研究。对于电池短期循环，已测量了内部电阻和时间常数，包括等效电路中电阻器和电容器的元件值。还测量了这些值对充电状态和温度的依赖性。结果证实镍铁电池可容纳比其标称电荷多25％的电荷。但是，这种增加的容量在60°C的温度下会消失，并可能因自放电而迅速消失。当用作长期能量存储的电解槽时，实验确定了每个电极与膜之间的分离间隙对于气体释放的重要性，并将该间隙的最佳尺寸确定为约1.25 mm。镍铁电池具有作为Power-to-X能量转换电解槽的可接受性能，但其大内阻将在5h充放电速率下（无论是否带有气泡分离膜）的电压效率限制在75％以内。