The development of low-cost and long-lasting all-climate cathode materials for the sodium ion battery has been one of the key issues for the success of large-scale energy storage. One option is the utilization of earth-abundant elements such as iron. Here, we synthesize a NASICON-type tuneable Na₄Fe₃(PO₄)₂(P₂O₇)/C nanocomposite which shows both excellent rate performance and outstanding cycling stability over more than 4400 cycles. Its air stability and all-climate properties are investigated, and its potential as the sodium host in full cells has been studied. A remarkably low volume change of 4.0% is observed. Its high sodium diffusion coefficient has been measured and analysed via first-principles calculations, and its three-dimensional sodium ion diffusion pathways are identified. Our results indicate that this low-cost and environmentally friendly Na₄Fe₃(PO₄)₂(P₂O₇)/C nanocomposite could be a competitive candidate material for sodium ion batteries.

We summarized the recent progress of cathode materials used for SIBs and modified strategies, expecting to give an inspiration for the development of high-performance cathode materials.