Highly flexible supercapacitors (SCs) have great potential in modern electronics such as wearable and portable devices. However, ultralow specific capacity and low operating potential window limit their practical applications. Herein, a new strategy for the fabrication of free‐standing NiMoS and NiFeS nanosheets (NSs) for high‐performance flexible asymmetric SC (ASC) through hydrothermal and subsequent sulfurization technique is reported. The effect of Ni²⁺ is optimized to attain hierarchical NiMoS and NiFeS NS architectures with high electrical conductivity, large surface area, and exclusive porous networks. Electrochemical properties of NiMoS and NiFeS NS electrodes exhibit that both have ultrahigh specific capacities (≈312 and 246 mAh g⁻¹ at 1 mA cm⁻²), exceptional rate capabilities (78.85% and 78.46% capacity retention even at 50 mA cm⁻², respectively), and superior cycling stabilities. Most importantly, a flexible NiMoS NS//NiFeS NS ASC delivers a high volumetric capacity of ≈1.9 mAh cm⁻³, excellent energy density of ≈82.13 Wh kg⁻¹ at 0.561 kW kg⁻¹, exceptional power density (≈13.103 kW kg⁻¹ at 61.51 Wh kg⁻¹) and an outstanding cycling stability, retaining ≈95.86% of initial capacity after 10 000 cycles. This study emphasizes the potential importance of compositional tunability of the NS architecture as a novel strategy for enhancing the charge storage properties of active electrodes.

中文翻译：

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等级Ni ？莫？S和Ni ？铁？具有超高能量密度的S纳米片，适用于柔性全固态超级电容器

高度灵活的超级电容器（SC）在现代电子产品（如可穿戴和便携式设备）中具有巨大的潜力。然而，超低的比容量和低的操作电势窗口限制了它们的实际应用。在此，自由站立的Ni的制造中的新战略沫 S和镍铁小号纳米片（NSS）高性能柔性不对称SC（ASC）通过水热法和随后的硫化技术的报道。Ni的作用²⁺被优化，以达到分层的Ni 沫 S和镍铁具有高电导率，大表面积和专用多孔网络的S NS体系结构。镍的电化学性能沫 S和镍铁小号NS电极表现出在都具有超高的比容量（≈312和246毫安克^-1在1mA厘米^-2），优异的速率能力（78.85％和78.46％的容量甚至在50 mA cm ^-2时仍保持不变），并具有出色的循环稳定性。最重要的是，柔性的Ni 沫小号NS //镍铁小号NS ASC提供≈1.9毫安厘米的高体积容量^-3≈82.13瓦公斤的，优异的能量密度^-1在0.561千瓦千克^-1，出色的功率密度（≈13.103千瓦千克^-1在61.51千克瓦^-1）和杰出的循环稳定性，10后保留的初始容量≈95.86％ 000个周期。这项研究强调了NS结构的组成可调性作为增强有源电极电荷存储特性的新策略的潜在重要性。