Zhang Rui, Zhu Xiaoxiao, Xie Tiancheng, Jiang Cairong, Ma Jianjun, Xie Chunlin, Ji Huimin, Wang Jin, Li Huanhuan, Wang Haiyan
Hunan Provincial Key Laboratory of Chemical Power Sources, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, P. R. China.
School of Materials Science and Engineering, Sichuan University of Science and Engineering, Zigong, Sichuan, 643000, P. R. China.
Small Methods. 2025 Jul;9(7):e2401884. doi: 10.1002/smtd.202401884. Epub 2025 Jan 5.
Anode-less sodium metal batteries (SMBs) suffer from the formation of Na dendrites and inactive Na on an anode substrate though showing advantages of high energy densities and low costs. Herein, N,O co-doped carbon spheres (NOCS), which are synthesized via a scalable polymerization and pyrolysis method, are employed as a thin and stable sodiophillic nucleation layer on the Cu foil. Combined with electrochemical measurements, Na deposition morphology observations and density functional theory calculations, it is revealed that the introduced N and O heteroatoms can greatly enhance the adsorption of Na on the carbon substrate and reduce the nucleation overpotential, thus forming sufficient seeding sites and guiding homogeneous Na deposition. Consequently, the NOCS coated Cu electrode achieves the outstanding reversibility of Na plating/stripping process over 1000 cycles at 2 mA cm with 2 mAh cm in asymmetric cells, as well as over 1000 h at 0.5 mA cm with 1 mAh cm in symmetric cells. Moreover, this modified Cu foil enables the anode-less full-cell with a high-loading NaV(PO) cathode to deliver a high initial capacity of 103 mAh g with a capacity retention of 79% after 350 cycles at 200 mA g, demonstrating the pave to the practical anode-less SMBs.
无阳极钠金属电池（SMB）尽管具有高能量密度和低成本的优势，但在阳极基底上会形成钠枝晶和无活性钠。在此，通过可扩展的聚合和热解方法合成的氮、氧共掺杂碳球（NOCS）被用作铜箔上薄而稳定的亲钠成核层。结合电化学测量、钠沉积形态观察和密度泛函理论计算表明，引入的氮和氧杂原子可以大大增强钠在碳基底上的吸附并降低成核过电位，从而形成足够的晶种位点并引导均匀的钠沉积。因此，涂覆有NOCS的铜电极在不对称电池中以2 mA cm²的电流密度和2 mAh cm²的面积容量实现了超过1000次循环的出色钠电镀/剥离过程可逆性，在对称电池中以0.5 mA cm²的电流密度和1 mAh cm²的面积容量实现了超过1000小时的可逆性。此外，这种改性铜箔使具有高负载NaV(PO) 阴极的无阳极全电池能够提供103 mAh g的高初始容量，在200 mA g下循环350次后容量保持率为79%，为实用的无阳极SMB铺平了道路。
