Baterías de metal líquido para almacenar electricidad procedente de las energías renovables

Científicos del MIT han creado una nueva batería que, según el equipo de investigadores, puede almacenar varias veces más electricidad que las baterías convencionales.

Una aplicación de este tipo podría tener importantes aplicaciones para regular tanto la energía eólica como la energía solar.

La nueva batería funcionaría de forma similar a una convencional, utilizando los tres componentes principales: un cátodo con carga positiva, un ánodo cargado negativamente y una membrana entre los dos.

Los metales líquidos almacenan la energía química, pero ninguno de los componentes son varillas sólidas, o cualquier tipo de producto químico sólido.

Las capas no se mezclan porque cada uno de los metales líquidos tiene un peso diferente. Dos de los materiales que actúan como electrodos del líquido son el magnesio fundido y el antimonio, mientras que el tercero es un electrolito líquido, formado por sulfuro de sodio. La composición exacta no ha sido revelada, y como es lógito cabe cierto escepticismo.

Liquid Metal Batteries to Store Renewable Energy
They can be used as back-ups for many systems

Liquid metal batteries are the way of the future, MIT researchers seem to think. They’ve created a prototype that can easily store several times more energy than conventional, solid ones, an innovation that could have numerous applications in storing the electricity created by renewable energy sources, such as solar power plants or wind farms. In addition, they could also be used for portable devices, such as mp3 players, laptops, cell phones and GPS devices.

Massachusetts Institute of Technology research expert Don Sadoway is one of the main proponents of the new technology. For the research, he has collaborated with David Bradwell, an MIT graduate student, and with Gerbrand Ceder, a fellow professor at the Institute.

Sadoway said that, “Since these batteries won’t be in someone’s hand or in a car, we don’t have to make them crash-worthy, idiot-proof, and it doesn’t have to operate at around body temperature.”

According to the scientist, the new class of batteries could also be used as emergency back-up systems for hospitals, and even federal or strategic buildings. “Our batteries have no solid materials in them; no solid electrodes, no solid membranes, no solid anything,” he added. There is no solid zinc or lithium in them, as opposed to the regular materials that can be found in remote control batteries.

The new cells work in very much the same way as regular ones do, in that they use the same three main components. They feature a positively charged cathode, a negatively charged anode, as well as a bridge between the two. Liquid metal batteries store energy chemically too, but the main difference is that none of the components are made from solid rods, or any kind of solid chemical.

After many years of trying different metals for his invention, Sadoway found the winning combination – antimony and magnesium provide the charged layers, while the bridge between them is made up of layers of sodium sulfide. The thing that prevents the materials from mixing is their own weight, which keeps them perfectly separated.

“This should be easy to scale up. If we want to make a battery the size of a 33 gallon garbage can, we can do it. If we want to make [it] the size of a football field, we could do it,” the researcher concluded, adding that the optimum size of the battery had yet to be determined, the prototypes being roughly the size of a soda can.