Li Shuhui, Wang Weihuang, Jia Yixin, Xu Huidong, Liu Rui, Wang Zheng, Xie Zicheng, Zhang Lantian, He Rong, Wang Liangbing
School of Materials Science and Engineering, Central South University, Changsha, Hunan, 410083, P. R. China.
State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, P. R. China.
Small Methods. 2025 Jul;9(7):e2402110. doi: 10.1002/smtd.202402110. Epub 2025 Jan 9.
Alluaudite-type NaFe(SO) (NFS) with high theoretical energy density is regarded as the promising cathode of sodium-ion batteries (SIBs), while practical rate and cyclic performances are still hindered by intrinsic poor conductivity. Here, a facile method is developed, collaborating high-boiling organic solvents assisted colloidal synthesis (HOS-CS) with sintering for tailoring NaFe(SO) nanocrystals decorated by conductive carbon network toward high-rate-capability cathode of SIBs. Impressively, the as-prepared NaFe(SO)@MC provides 60.6 and 46.9 mAh g of reversible capacities even at ultrahigh rates of 20 and 30 C, respectively, ranking the superior state among the current NFS-based cathode. More importantly, NaFe(SO)@MC achieves 73% of capacity retention at 20 C after 500 cycles, highlighting its potential for application as a fast chargeable cathode. As a bonus, the full-cell configuration constructed with NaFe(SO)@MC cathode and commercial hard carbon (HC) anode delivers 45.6 mAh g at 10 C and 68.3 mAh g of initial capacity with ≈79.4% of retention after 100 cycles at 2 C. Also, NaFe(SO)@MC||HC full cell supplies as high as 140 Wh kg of practical energy density. This work offers a novel approach to prepare NFS cathode for SIBs with both high energy density and fast-charging ability.
具有高理论能量密度的钠铁硫酸盐（Alluaudite-type NaFe(SO) ，NFS）被认为是有前景的钠离子电池（SIBs）正极材料，然而其实际倍率性能和循环性能仍受限于固有的低电导率。在此，我们开发了一种简便方法，将高沸点有机溶剂辅助胶体合成法（HOS-CS）与烧结相结合，用于制备由导电碳网络修饰的NaFe(SO)纳米晶体，以实现具有高倍率性能的SIBs正极。令人印象深刻的是，所制备的NaFe(SO)@MC即使在20 C和30 C的超高倍率下，可逆容量分别达到60.6和46.9 mAh g，在目前基于NFS的正极材料中处于领先水平。更重要的是，NaFe(SO)@MC在20 C下经过500次循环后容量保持率达到73%，突出了其作为快速充电正极材料的应用潜力。此外，由NaFe(SO)@MC正极和商业硬碳（HC）负极构建的全电池在10 C下可逆容量为45.6 mAh g，初始容量为68.3 mAh g，在2 C下经过100次循环后容量保持率约为79.4%。而且，NaFe(SO)@MC||HC全电池的实际能量密度高达140 Wh kg。这项工作为制备具有高能量密度和快速充电能力的SIBs的NFS正极提供了一种新方法。
