Pseudocapacitance points out a new direction for the recent research and development of potassium ion anode materials because of its fast energy storage kinetics, which has yielded lots of successful pseudocapacitance-rich examples by introducing more active sites such as doped heteroatoms. However, the negative reactions with the electrolyte in electrochemical process often cause the serious inactivation of active sites, giving a hit for seeking higher pseudocapacitance. In this work we proposed a new strategy to wrap the protective shield for the pseudocapacitance-rich materials to alleviate this matter. By the ultrasonic-induced rGO self-encapsulation of S, N dual-doped carbon spheres, the directional contact between active sites and the electrolyte is blocked, while the rGO films with enlarged interlayer spacing and lots of defects also like filter membrane, accelerate the K⁺ desolvation and fast diffusion into carbon matrix. Benefiting from the synergistic effect of rGO shielding and filtrating, the pseudocapacitance of S, N dual-doping carbon spheres is fully activated. As the potassium-ion battery anode, the obtained S, N dual-doping carbon sphere@rGO delivers a state-of-the-art capacity of 596 mAh g⁻¹, which achieves a 52.5 % capacity enhancement in contrast to that without rGO shield. As a proof of application, the resultant high-pseudocapacitance carbon anode is incorporated into a potassium ion hybrid capacitor, showing the most favorable capacity-cyclability combinations with the high energy–density of 83 Wh kg⁻¹ after 6500 cycles at 5A g⁻¹.

赝电容因其快速的储能动力学特性为钾离子负极材料的近期研究和开发指明了新的方向，并通过引入更多的活性位点（如掺杂杂原子）产生了许多成功的富含赝电容的例子。然而，电化学过程中与电解质的负反应往往会导致活性位点的严重失活，从而为寻求更高的赝电容带来了冲击。在这项工作中，我们提出了一种新的策略来包裹富赝电容材料的保护罩，以缓解这一问题。通过超声诱导的 rGO 自封装 S、N 双掺杂碳球，阻断了活性位点与电解质之间的定向接触，⁺去溶剂化和快速扩散到碳基质中。受益于rGO屏蔽和过滤的协同作用，S、N双掺杂碳球的赝电容被充分激活。作为钾离子电池负极，所获得的 S、N 双掺杂碳球@rGO 提供了 596 mAh g ^-1的最新容量，与没有 rGO 的情况相比，容量提高了 52.5%盾。作为应用证明，将所得的高赝电容碳阳极结合到钾离子混合电容器中，在 5A g ^{-1下 6500 次循环后显示出最有利的容量循环组合和 83 Wh kg -1}的高能量密度.