High-Performance Pseudocapacitive Microsupercapacitors from Laser-Induced Graphene
High-Performance Pseudocapacitive Microsupercapacitors from Laser-Induced Graphene
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DOI：
10.1002/adma.201503333
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发表时间：
2016-02-03
影响因子：
29.4
通讯作者：
Tour, James M.
中科院分区：
文献类型：
--
作者：
Li, Lei;Zhang, Jibo;Tour, James M.
DOI：10.1002/ADMA。201503333器件由其电容和工作电压(E=Cv2/2)决定，[20]进一步提高其储能能力有赖于提高这两个参数中的任何一个。为了增加器件电容，将过渡金属氧化物[10，12，21-23]和导电聚合物[24，25]等伪电容材料加载到电极上，以提供来自表面氧化还原反应的伪电容。然而，这种制造策略受到高成本图案化工艺或苛刻的合成条件的限制，从而减缓了在商品电子设备中的部署。另外，有机电解液具有更高的工作电压，从而进一步提高了储能性能。[26]然而，安全问题、复杂的制造工艺和严格的有机电解液使用条件限制了它们的广泛应用。[26]另一种方法是在不使用有机电解液的情况下制备非对称MSCs。[27]最近，我们团队开发了一种简单且可扩展的方法，通过在空气中激光写入图案在聚酰亚胺(PI)衬底上制备图案化的多孔石墨烯，所得到的激光诱导石墨烯(LIG)在小型化储能装置中显示了其良好的应用前景。我们将激光感应工艺和随后的电沉积伪电容材料相结合，制备出了具有极大改善电化学性能的全固态、柔性对称和不对称MSC器件。首次使用CO2激光器将PI转化为具有交指结构的多孔LIG，它不仅可以作为EDLC电极，而且可以作为电沉积伪电容材料的柔性和导电基质。将代表过渡金属氧化物和导电聚合物的两种伪电容材料二氧化锰(MnO2)或氢氧化铁(FeOOH)和聚苯胺(PANI)电沉积到LIG上，形成LIG-MnO2、LIG-FeOOH和LIG-PANI复合材料。然后将它们组装成全固态柔性对称LIG-MnO2-MSCs和LIG-PANI-MSCs，以及使用LIG-FeOOH作为负极和LIG-MnO2作为正极的不对称MSCs(LIG-FeOOH//LIG-MnO2)，由于定义良好的图案避免了电极短路，因此不存在集流器、粘结剂和分离器。所有这些设备都显示出与微电池相当的能量密度，而不会牺牲其良好的倍率性能、循环稳定性和机械灵活性。
DOI: 10.1002/adma. 201503333 device is determined by its capacitance and working voltage (E= CV2/2),[20] further improvement of its energy storage relies on enhancing either of these parameters. To increase device capacitance, pseudocapacitive materials, such as transition metal oxides [10, 12, 21–23] and electrically conductive polymers,[24, 25] are loaded onto the electrodes to provide pseudocapacitance from surface redox reactions. However, this fabrication strategy is limited by either high-cost patterning processes or harsh synthetic conditions, slowing deployment in commodity electronic devices. Alternatively, organic electrolytes are used for their higher working voltage, resulting in further improvement in energy storage.[26] However, safety issues, complex fabrication processes, and strict conditions for the use of organic electrolytes have limited their widespread application.[26] An alternative approach is to make asymmetric MSCs without using an organic electrolyte.[27]Recently, our group developed a simple and scalable method to prepare patterned porous graphene on a polyimide (PI) substrate by laser-writing patterns in air, and the resulting laserinduced graphene (LIG) showed its promising applications in miniaturized energy storage devices.[28–30] Here, we combine the laser induction process with subsequent electrodeposition of pseudocapacitive materials for the fabrication of all-solidstate, flexible symmetric and asymmetric MSC devices that show greatly improved electrochemical performance. A CO 2 laser is first used to convert the PI into porous LIG with an interdigitated architecture, which works not only as EDLC electrodes but also as a flexible and conductive matrix for the electrodeposition of pseudocapacitive materials. Two types of pseudocapacitive materials, manganese dioxide (MnO 2) or ferric oxyhydroxide (FeOOH), and polyaniline (PANI), representing characteristic transition metal oxides and conductive polymers, are electrodeposited onto the LIG forming LIG–MnO 2, LIG–FeOOH, and LIG–PANI composites. They are then assembled into all-solid-state flexible symmetric LIG–MnO 2–MSCs and LIG–PANI–MSCs, and asymmetric MSCs using LIG–FeOOH as a negative electrode and LIG–MnO 2 as a positive electrode (LIG–FeOOH//LIG–MnO 2) that are free of current collectors, binders, and separators due to the well-defined patterns that avoid short circuiting the electrodes. All of these devices demonstrate comparable energy densities to microbatteries without sacrificing their good rate performance, cycling stability, and mechanical flexibility.