Hu Weijiang, Huang Ziling, Li Yajun, Pan Limei, Li Qian, Yang Jun, Cao Liang, Yu Lei, Yang Jian
College of Materials Science and Engineering, Nanjing Tech University, Nanjing, Jiangsu 211816, China; Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China.
School of Materials Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China.
J Colloid Interface Sci. 2025 Apr;683(Pt 2):954-963. doi: 10.1016/j.jcis.2024.12.223. Epub 2024 Dec 30.
Sodium metal is heralded as a premier anode candidate poised to supplant lithium in next-generation rechargeable batteries due to its abundant availability, cost-effectiveness, and superior energy density. Due to the highly reactive nature of metallic sodium, an unstable solid electrolyte interphase (SEI) forms spontaneously on the Na metal anode. This instability leads to non-uniform sodium deposition during cycling, promoting dendrite growth and the accumulation of "dead" sodium. As a result, the cycling lifespan is significantly reduced, creating further complications. Herein, a facile in situ artificial interfacial layer of gallium phosphide (GaP) has been successfully constructed on the surface of sodium metal via a one-step method. This novel GaP protective layer, uniformly and densely distributed, effectively mitigates the instability of the sodium metal anode during the stripping/deposition process, resulting in enhanced structural integrity and the absence of dendritic growth. The Na/GaP symmetric cell exhibits low polarization voltage and a decreased energy barrier for Na diffusion during cycling, enabling stable operation for over 1200 h at a current density of 0.5 mA cm (1 mAh cm). The inhibitory effect of the GaP interfacial layer on dendrite formation and the uniform deposition enhancement during the stripping and deposition processes of sodium metal anode were verified through in situ optical microscopy, along with complementary ex situ scanning electron microscope (SEM) and x-ray photoelectron spectroscopy (XPS) characterizations. After 1100 cycles at a high current rate of 5 C, a full cell made with a NaV(PO) (NVP) cathode and a Na/GaP anode exhibits a reversible capacity of 90 mAh g. The NVP||Na/GaP complete cell also produces a remarkable energy density of 352.2 Wh kg. This work offers unique insights for the facile construction of mono-component sodium metal anode interfacial coatings and their related applications.
金属钠被誉为下一代可充电电池中有望取代锂的首要阳极候选材料，因其储量丰富、成本效益高且能量密度优越。由于金属钠具有高反应活性，在钠金属阳极上会自发形成不稳定的固体电解质界面（SEI）。这种不稳定性导致循环过程中钠沉积不均匀，促进枝晶生长和“死”钠的积累。结果，循环寿命显著缩短，引发更多复杂问题。在此，通过一步法成功在钠金属表面构建了一层简易的原位磷化镓（GaP）人工界面层。这种新型的GaP保护层均匀且致密地分布，有效减轻了钠金属阳极在剥离/沉积过程中的不稳定性，增强了结构完整性且无枝晶生长。Na/GaP对称电池在循环过程中表现出低极化电压和降低的钠扩散能垒，在0.5 mA cm（1 mAh cm）的电流密度下能够稳定运行超过1200小时。通过原位光学显微镜以及辅助的非原位扫描电子显微镜（SEM）和X射线光电子能谱（XPS）表征，验证了GaP界面层对钠金属阳极在剥离和沉积过程中枝晶形成的抑制作用以及均匀沉积增强效果。在5 C的高电流速率下经过1100次循环后，由NaV(PO)（NVP）阴极和Na/GaP阳极制成的全电池表现出90 mAh g的可逆容量。NVP||Na/GaP全电池还产生了352.2 Wh kg的显著能量密度。这项工作为单组分钠金属阳极界面涂层的简易构建及其相关应用提供了独特见解。
