Zheng Shuanghao, Wang Sen, Dong Yanfeng, Zhou Feng, Qin Jieqiong, Wang Xiao, Su Feng, Sun Chenglin, Wu Zhong-Shuai, Cheng Hui-Ming, Bao Xinhe
Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China.
State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China.
Adv Sci (Weinh). 2019 Oct 4;6(23):1902147. doi: 10.1002/advs.201902147. eCollection 2019 Dec.
With the relentless development of smart and miniaturized electronics, the worldwide thirst for microscale electrochemical energy storage devices with form factors is launching a new era of competition. Herein, the first prototype planar sodium-ion microcapacitors (NIMCs) are constructed based on the interdigital microelectrodes of urchin-like sodium titanate as faradaic anode and nanoporous activated graphene as non-faradaic cathode along with high-voltage ionogel electrolyte on a single flexible substrate. By effectively coupling with battery-type anode and capacitor-type cathode, the resultant all-solid-state NIMCs working at 3.5 V exhibit a high volumetric energy density of 37.1 mWh cm and an ultralow self-discharge rate of 44 h from to 0.6 , both of which surpass most reported hybrid micro-supercapacitors. Through tuning graphene layer covered on the top surface of interdigital microelectrodes, the NIMCs unveil remarkably enhanced power density, owing to the establishment of favorable multidirectional fast ion diffusion pathways that significantly reduce the charge transfer resistance. Meanwhile, the as-fabricated NIMCs present excellent mechanical flexibility without capacitance fade under repeated deformation, and electrochemical stability at a high temperature of 80 °C because of using nonflammable ionogel electrolyte and in-plane geometry. Therefore, these flexible planar NIMCs with multidirectional ion diffusion pathways hold tremendous potential for microelectronics.
随着智能和小型化电子产品的不断发展，全球对具有特定外形尺寸的微型电化学储能装置的需求正在开启一个新的竞争时代。在此，首个原型平面钠离子微型电容器（NIMC）基于海胆状钛酸钠叉指微电极作为法拉第阳极、纳米多孔活性石墨烯作为非法拉第阴极，并在单个柔性基板上搭配高压离子凝胶电解质构建而成。通过有效地将电池型阳极和电容器型阴极耦合，所得的全固态NIMC在3.5V下工作，展现出37.1mWh/cm³的高体积能量密度和从1V到0.6V的44小时超低自放电率，这两者均超过了大多数已报道的混合微型超级电容器。通过调整覆盖在叉指微电极顶表面的石墨烯层，NIMC展现出显著增强的功率密度，这归因于建立了有利的多向快速离子扩散路径，该路径显著降低了电荷转移电阻。同时，所制备的NIMC具有出色的机械柔韧性，在反复变形下电容不衰减，并且由于使用了不可燃的离子凝胶电解质和平面几何结构，在80°C的高温下具有电化学稳定性。因此，这些具有多向离子扩散路径的柔性平面NIMC在微电子领域具有巨大潜力。
