Microfabricated Pseudocapacitors Using Ni(OH)2 Electrodes Exhibit Remarkable Volumetric Capacitance and Energy Density
Microfabricated Pseudocapacitors Using Ni(OH)2 Electrodes Exhibit Remarkable Volumetric Capacitance and Energy Density
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DOI：
10.1002/aenm.201401303
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发表时间：
2015
影响因子：
27.8
通讯作者：
Narendra Kurra;Nuha A. Alhebshi;H. Alshareef
中科院分区：
文献类型：
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作者：
Narendra Kurra;Nuha A. Alhebshi;H. Alshareef
以氢氧化物金属为基础的微加工伪电容器具有令人印象深刻的体积堆叠电容和能量密度。采用自顶向下的光刻工艺和自底向上的化学合成相结合的方法制备微伪电容器（μ伪电容器）。由此得到的Ni(OH)2基器件具有几个优异的特性，包括高达500 V - s-1的高速率氧化还原活性和16 mF cm-2的面积电池电容，对应于325 F cm-3的体积堆叠电容。这种体积电容比具有交错电极结构的碳和金属氧化物基μ超级电容器高两倍。此外，这些μ‐伪电容器的最大能量密度为21 mWh cm-3，优于锂基薄膜电池。在化学浴沉积过程中，Ni(OH)2在Ni表面的非均匀生长是形成具有垂直取向的均匀单片Ni(OH)2介孔纳米片的关键参数，也是制备器件具有优异性能的原因。此外，该μ‐伪电容器的串联功能配置被证明能够为发光二极管供电。
Metal hydroxide based microfabricated pseudocapacitors with impressive volumetric stack capacitance and energy density are demonstrated. A combination of top‐down photolithographic process and bottom‐up chemical synthesis is employed to fabricate the micro‐pseudocapacitors (μ‐pseudocapacitors). The resulting Ni(OH)2‐based devices show several excellent characteristics including high‐rate redox activity up to 500 V s–1 and an areal cell capacitance of 16 mF cm–2 corresponding to a volumetric stack capacitance of 325 F cm–3. This volumetric capacitance is two‐fold higher than carbon and metal oxide based μ‐supercapacitors with interdigitated electrode architecture. Furthermore, these μ‐pseudocapacitors show a maximum energy density of 21 mWh cm–3, which is superior to the Li‐based thin film batteries. The heterogeneous growth of Ni(OH)2 over the Ni surface during the chemical bath deposition is found to be the key parameter in the formation of uniform monolithic Ni(OH)2 mesoporous nanosheets with vertical orientation, responsible for the remarkable properties of the fabricated devices. Additionally, functional tandem configurations of the μ‐pseudocapacitors are shown to be capable of powering a light‐emitting diode.