Co-intercalation reaction for graphite in sodium ion batteries: Revival or revolution?

Reversible intercalation of guest ions in graphite laid the foundation of modern battery technology, exemplified by the successful launch of Li-ion batteries (LIBs) 35 years ago. With sodium’s natural abundance and low cost, sodium ion batteries (SIBs) are increasingly regarded an appealing contender for large-scale energy storage. However, the conventional intercalation chemistry that unlocks graphite anodes in LIBs is ineffective in SIBs. This obstacle is recently overcome by a co-intercalatio