Researchers at Murdoch University in Perth, Australia have developed a sodium-ion battery that could make renewable energy technologies more affordable. The salt battery can be used in place of more expensive lithium ion batteries to store solar and wind energy so as to provide continuous power even on cloudy or windless days. According to project leaders Drs Manickam Minakshi and Danielle Meyrick, the battery “has excellent potential for large-scale use, including storing energy from wind turbines and solar farms for later feeding into local electricity grids, as well as use in industry”.
As we look to transition to renewable energy sources such as solar energy and wind power we are faced with a number of problems. Currently wind turbines and solar panels are dependent on weather conditions; wind turbines don’t operate on a still day, while solar panels can’t be used at night or during cloudy weather. It can leave the electricity demand unbalanced with the energy supply generated by renewables. These limitations require the storing of excess energy where possible so as to remain entirely off-the-grid, and the new water-based sodium-ion battery is the most affordable, low-temperature energy storage created so far.
Previous storage batteries have been using rare and expensive compounds like molten sulfur and liquid metals, making the price too steep for commercialization. Unlike its predecessors, the new battery is based on globally abundant and affordable sodium, whose chemical properties are similar to the widely-used lithium.
The next challenge was to find a material for cathodes and anodes capable of accommodating sodium’s ionic size. After extensive testing, Drs Manickam Minakshi and Danielle Meyrick have found that using manganese dioxide as the cathode and a novel olivine sodium phosphate as the anode gave best results.
Claiming that this breakthrough will make renewable energy more accessible in developing countries, Dr Manickam Minakshi states that the “research has reached the stage where we’re ready to move beyond our lab towards larger-scale commercialization”.