Unleashing the electrochemical potential of NaNiFeMnO2 layered oxide cathodes through titanium and copper co-enhancement for sodium ion batteries

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2025-02, Vol.978, p.118870, Article 118870
• Main Authors: Bibi, Safia, Bashir, Ahmed, Abideen, Zain Ul, Chen, Tao, Sun, Dan, Liu, Kaiyu
• Format: Article
• Language: English
• Subjects: Cathode; Doping; Layered oxides; Sodium-ion batteries; Stability
• ISSN: 1572-6657
• DOI: 10.1016/j.jelechem.2024.118870

•Cu/Ti has been co-doped in O3-NaNi1/3Fe1/3Mn1/3O2 (NaNFM).•Cu/Ti doping increased the thickness of transition metal and Na+ layers.•Cu/Ti doping improved electronic conductivity and Na+ diffusion coefficient.•Compared with un-doped NaNFM, the Cu/Ti co-doped showed enhanced performance.•This effective strategy has promising potential for the development of high-performance SIBs. Sodium-ion batteries hold a great importance in power storage devices due to affordable price and earth abundancy. However, the complex phase evolution during Na+ ions insertion/extraction severely limits their durability and rate capability, which largely limits their practical applications. Herein, we have successfully synthesized O3-type Na1.05 (Ni0.33Fe0.33Mn0.33)0.83Ti0.05Cu0.12O2 (NaTiCuNFM). It was found that the as-obtained NaTiCuNFM exhibits enhanced rate performance as well as specific discharge capacity of 124.5 mAhg−1 at the rate of 1C with 82 % capacity retention after 200 cycles. Besides, at high current density of 10C, the obtained NaTiCuNFM shows a high initial discharge capacity of 99 mAhg−1 which was significantly higher than that of NaNFM (61 mAh/g). The higher performance of Cu/Ti co-doped NaTiCuNFM was attributed to the enhancement of inter sodium layer spacing resulting an easy migration of sodium ions, which leads to the enhanced Na+ diffusion and rate performance. The co-doping of Cu/Ti has proven to provide a more stable structure. Our obtained results, will open a new window for bi-metals doped cathode materials for practical battery application.