Sn4+xP3 @ amorphous Sn-P composites as anodes for sodium-ion batteries with low cost, high capacity, long life, and superior rate capability

The effective usage of renewable energy sources, such as solar and wind, is the key to building a more sustainable society and reducing emissions of the main greenhouse gas (CO2). Nowadays, the great challenge is how to store renewable energy in a cheap and effi cient way; that is to say, an energy storage system for renewable energy requires low cost, high power capability, relatively good energy density, and high safety. Na-ion batteries (SIBs), which have been attracting more attention owing to their low cost, could potentially be the most promising candidate for stationary batteries.