Revitalizing sodium-ion batteries via controllable microstructures and advanced electrolytes for hard carbon

Sodium-ion batteries (SIBs) with low cost and high safety are considered as an electrochemical energy storage technology suitable for large-scale energy storage. Hard carbon, which is inexpensive and has both high capacity and low sodium storage potential, is regarded as the most promising anode for commercial SIBs. However, the commercialization of hard carbon still faces technical issues of low initial Coulombic efficiency, poor rate performance, and insufficient cycling stability, due to the intrinsically irregular microstructure of hard carbon. To address these challenges, the rational design of the hard carbon microstructure is crucial for achieving high-performance SIBs, via gaining an in-depth…