The transition metal selenite CoSeO₃ single crystal nanoparticles with primary particle size distribution ranging from 80 to 200 nm is systematically investigated as anode material for sodium ion batteries (SIBs)/capacitors (SICs). It achieves stable Na⁺ storage capacity of 280 mAh g^-1 at a high current density of 10 A g^-1 in CoSeO₃||Na SIBs. Furthermore, the corresponding CoSeO₃||Activated carbon (AC) SICs also presents a high energy density of 51 Wh kg^-1 at a power density of 2 kW kg^-1, along with 72% energy retention after 3000 cycles at 1 A g^-1. Combining advanced microscopy (HRTEM, SEM), density functional theory (DFT) calculations and surface science (XPS), it is demonstrated that the CoSeO₃ in-situ transform into binary oxides CoO/SeO₂ and form heterointerfaces during the initial discharge/charge cycle. The coupled heterointerfaces between CoO and SeO₂ could construct strong internal electric field, accelerating the electron/Na⁺ diffusion kinetics during the subsequent charge-discharge process and boosting Na⁺ pseudocapacitance storage. The finding of heterointerfaces synergistic sodium-ion storage fundamental mechanism of transition metal selenite might provide inspiration for the development of new anode material for sodium-based storage devices.

作为钠离子电池（SIBs）/电容器（SICs）的负极材料，系统研究了初级粒径分布范围为80-200nm的过渡金属亚硒酸盐CoSeO ₃单晶纳米粒子。它在 CoSeO ₃ ||Na SIBs 中以 10 A g ^-1的高电流密度实现了 280 mAh g ^{-1 的}稳定 Na ⁺存储容量。此外，相应的 CoSeO ₃ ||活性炭 (AC) SIC在 2 kW kg ^-1的功率密度下也表现出 51 Wh kg ^-1的高能量密度，以及在 1 A g 下 3000 次循环后的 72% 能量保持率^-1. 结合先进的显微镜 (HRTEM, SEM)、密度泛函理论 (DFT) 计算和表面科学 (XPS)，证明 CoSeO ₃原位转变为二元氧化物 CoO/SeO ₂并在初始放电/充电期间形成异质界面循环。CoO和SeO ₂之间的耦合异质界面可以构建强大的内部电场，在随后的充放电过程中加速电子/Na ^{+ 的}扩散动力学并提高Na ⁺赝电容存储。过渡金属亚硒酸盐异质界面协同钠离子存储基本机理的发现可能为钠基存储器件新型负极材料的开发提供启示。