Technion M.Sc. student Lihi Amit has found a way to lower the cost of replacing the membrane of rechargeable batteries by finding an alternative method to do so.
While renewable resources promise unlimited and clean energy production, that promise can't always be fulfilled. Varying factors, such as wind and sunlight, are not always in constant supply, making energy storage a necessity in energy harvesting. In addition, the rechargeable batteries used to store such energy production are quite costly.
The 'flow batteries' that are ordinarily used consist of two electrolyte liquids with opposite charges that are pumped through the battery. A 'selective membrane' keeps the battery from self-discharging so that the chemicals interacting on the two electrode conductors can create a current.
The downside to the flow battery is that its membrane is expensive and requires constant repair, amounting to 40% of the battery's cost.
Amit used bromine and zinc – both cheap materials – and coupled them with a generic complexing agent to trap bromine in droplets, mimicking an oil-and-water effect in the battery, to prevent the electrolytes from flowing together, mixing and self-discharging, the same way the membrane does.
This allowed for a controlled release of the bromine to keep the electric current flowing, creating a fluid membrane of single droplets. Cheaper batteries could make solar, wind, and other renewable sources, that are not always present and usually require special storage, a more reliable option for energy production.
Amit conducted the study with the help of Technion Faculty of Mechanical Engineering Professor Matthew Suss, Danny Naar, Dr. Robert Gloukhovski and Dr. Gerardo Jose la O’ from Primus Power Inc, which was published in ChemSusChem.