Solution‐based techniques are considered as a promising strategy for scalable fabrication of flexible electronics owing to their low‐cost and high processing speed. The key to the success of these techniques is dominated by the ink formulation of active nanomaterials. This work successfully prepares a highly concentrated two dimensional (2D) crystal ink comprised of ultrathin nickel hydroxide (Ni(OH)₂) nanosheets with an average lateral size of 34 nm. The maximum concentration of Ni(OH)₂ nanosheets in water without adding any additives reaches as high as 50 mg mL⁻¹, which can be printed on arbitrary substrates to form Ni(OH)₂ thin films. As a proof‐of‐concept application, Ni(OH)₂ nanosheet ink is coated on commercialized carbon fiber yarns to fabricate wearable energy storage devices. The thus‐fabricated hybrid supercapacitors exhibit excellent flexibility with a capacitance retention of 96% after 5000 bending–unbending cycles, and good weavability with a high volumetric capacitance of 36.3 F cm⁻³ at a current density of 0.4 A cm⁻³, and an energy density of 11.3 mWh cm⁻³ at a power density of 0.3 W cm⁻³. As a demonstration of practical application, a red light emitting diode can be lighted up by three hybrid devices connected in series.

中文翻译：

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高浓度，超薄氢氧化镍纳米片油墨，用于可穿戴式储能设备

基于解决方案的技术因其低成本和高处理速度而被认为是可扩展制造柔性电子产品的策略。这些技术成功的关键在于活性纳米材料的油墨配方。这项工作成功地制备了由超薄氢氧化镍（Ni（OH）₂）纳米片组成的高度浓缩的二维（2D）晶体墨水，平均横向尺寸为34 nm。不添加任何添加剂的水中Ni（OH）₂纳米片的最大浓度高达50 mg mL ^-1，可以将其印刷在任意基材上以形成Ni（OH）₂薄膜。作为概念验证应用，Ni（OH）₂将纳米片油墨涂覆在商品化的碳纤维纱上，以制造可穿戴的能量存储设备。如此制成的混合超级电容器具有出色的柔韧性，经过5000次弯曲-弯曲处理后仍保持96％的电容，并具有良好的可编织性，在0.4 A cm ^-3的电流密度下具有36.3 F cm ^-3的高体积电容，并且的11.3厘米mWh的能量密度^-3在0.3瓦厘米的功率密度^-3。作为实际应用的演示，红色发光二极管可以通过串联的三个混合设备点亮。