A state-of-the-art approach has been performed to stabilize the surface of P2-type (Na_0.66Mn_0.54Ni_0.13Co_0.13O₂ (NMNC)) material through the atomic layer deposition (ALD) of Al₂O₃ (10 ALD cycles) to fabricate a 3 V sodium ion capacitor (NIC) with ultrahigh rate stability. This is the first known report of stabilizing the NIC electrode surface by a metal oxide coating using ALD. The capacitor constructed with an Al₂O₃-coated NMNC (NMNC-Al) cathode and a commercial activated carbon (CAC) anode in an organic electrolyte delivers a discharge capacitance of 68 F g⁻¹ at 0.35 A g⁻¹ current density and exhibits extremely high electrochemical stability of ~ 98% of its initial value after 10,000 cycles. In contrast, the capacitor containing a pristine NMNC electrode displays a capacity retention of 78%. The NMNC-Al/CAC cell also has an energy density of 63 Wh kg⁻¹ at a power density of 6.6 kWh kg⁻¹. The capacitance, energy, and power densities obtained from the NMNC-Al/CAC cell are the best-reported values for sodium-based capacitors and outperforms well-established lithium ion capacitors. The electrochemical impedance spectroscopy study reveals that the sluggish reaction kinetics of the NMNC electrode at high current density is successfully overcome by coating an ultrathin Al₂O₃ layer by ALD on its surface.

国家的最先进的方法已被执行到P2型的表面稳定（钠_0.66锰_0.54镍_0.13钴_0.13 Ô ₂（NMNC））通过Al的原子层沉积（ALD）材料₂ Ô ₃（ 10个ALD周期）来制造具有超高速率稳定性的3 V钠离子电容器（NIC）。这是通过使用ALD的金属氧化物涂层来稳定NIC电极表面的第一个已知报告。由涂有Al ₂ O ₃的NMNC（NMNC-Al）阴极和有机电解质中的商用活性炭（CAC）阳极构成的电容器可提供68 F g ^-1的放电电容电流密度为0.35 A g ^-1时，在10,000次循环后显示出极高的电化学稳定性，约为初始值的98％。相反，包含原始NMNC电极的电容器显示的容量保持率为78％。NMNC-Al / CAC电池在6.6 kWh kg ^-1的功率密度下也具有63 Wh kg ^-1的能量密度。从NMNC-Al / CAC电池获得的电容，能量和功率密度是钠基电容器的最佳报告值，并且胜过了公认的锂离子电容器。电化学阻抗谱研究表明，通过涂覆超薄Al ₂ O ₃可成功克服NMNC电极在高电流密度下反应迟钝的反应动力学 在其表面上通过ALD进行涂层。