Layered two-dimensional (2D) nanomaterials are highly promising for boosting energy density of supercapacitors for industrial translation, however their rate performances are limited by the intrinsically sluggish ion transport within sub-nanochannels. Herein, we elaborate and prove a novel concept of electrostatic-repulsion-enabled ionophobic and hydrogen-bonding-enabled hydrophilic surface to substantially enhance ion transport and charging dynamics in sub-nanochannels. The concept is experimentally and theoretically developed through constructing less negatively-charged (-OH terminated) MXene nanochannels and molecular dynamics (MD) studies of electrolyte dynamics in MXene nanochannels with different functional groups, revealing that -OH terminations enable hydrophilic but ionophobic features for unimpeded ion transport. The ion transport mechanisms during the negative charge are further revealed by electrochemical quartz crystal microbalance tests. Electrochemical measurements demonstrate that hydrophilic but ionophobic sub-nanochannels feature drastically reduced ion diffusion resistance (by 90%) and significantly-improved rate performance (from 20.4% to 78.4% at 50 A g^–1). The universality of this sub-nanochannel engineering concept is validated in acid electrolyte and composite materials, making it potentially applicable across diverse areas of nanoscience and nanotechnology.

分层二维 (2D) 纳米材料在提高超级电容器的能量密度以进行工业转化方面非常有前途，但它们的倍率性能受到亚纳米通道内固有的缓慢离子传输的限制。在此，我们阐述并证明了静电排斥启用的离子疏水性和氢键启用的亲水表面的新概念，以显着增强亚纳米通道中的离子传输和充电动力学。该概念是通过构建带较少负电荷（-OH 终止）的MXene纳米通道和分子动力学 (MD) 对具有不同官能团的 MXene 纳米通道中电解质动力学的研究表明，-OH 端基具有亲水但疏离子的特性，可实现畅通无阻的离子传输。电化学石英晶体微天平测试进一步揭示了负电荷期间的离子传输机制。电化学测量表明，亲水但疏离子的亚纳米通道具有显着降低离子扩散阻力（90%）和显着提高倍率性能（在 50 A g –1 时从 20.4% 到 78.4%）的^特点。这种亚纳米通道工程概念的普遍性在酸性电解质和复合材料中得到验证，使其有可能适用于纳米科学和纳米技术的各个领域。