at 0.1 and 20C, respectively), with 98.2% capacity retention after 2000 cycles at 20 C. Moreover, the corresponding pouch cells stably operate for 500 cycles with 80.9% capacity retention. Rather than simply increasing Na occupancy at pre-existing Na sites, this sodium-rich site strategy introduces new Na sites at specific lattice positions, providing a viable design paradigm for advancing low-cost polyanionic Na-storage materials.
Wáng et al. (2026) studied this question.