A flexible Ni3S2/Ni@CC electrode for high-performance battery-like supercapacitor and efficient oxygen evolution reaction

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2021-09, Vol.420, p.127646, Article 127646
• Main Authors: Qian, Hao, Wu, Baoxin, Nie, Zhongwu, Liu, Tiantian, Liu, Peng, He, Hao, Wu, Jianghong, Chen, Zhaoyong, Chen, Shuguang
• Format: Article
• Language: English
• Subjects: Flexible; Ni3S2; OER; Supercapacitor
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.127646

[Display omitted] •A flexible Ni3S2/Ni@CC electrode is fabricated.•The all-solid-state ASC delivers 0.27 mWh cm−2 and superior mechanical flexibility.•The electrode demonstrates η10 of 290.9–300.8 mV for OER at angles from 0 to 180°.•The good OER activity is supposed as the synergy effect of Ni3S2(OH)x and Ni3S2. The flexible electrodes with battery-like capacitive active materials or efficient electrocatalysts are highly desirable for flexible electronics and portable devices. Here we develop a highly flexible Ni3S2@Ni/CC electrode via a facile and scalable nickel electroplating and in-situ sulfuration route. When it acts as a supercapacitor electrode, the assembled all-solid-state hybrid supercapacitor delivers a high areal energy density of 0.27 mWh cm−2 at an areal power density of 4.90 mW cm−2. Because of its superior mechanical flexibility, the assembled supercapacitor exhibits 88.1% retention of its initial capacitance after 2000 bending cycles from 0° to 90°. Furthermore, the Ni3S2@Ni/CC electrode exhibits high activity for oxygen evolution reaction (OER), achieving a benchmark of 10 mA cm−2 at a relatively low overpotential (η10) of 290.9 mV with a Tafel slope of 101.26 mV dec−1. Slight increments of 9.9 mV in η10 and 6.55 mV dec−1 in Tafel slope are obtained even when the electrode is tested under a bending angle of 180°. Meanwhile what it delivers an excellent long-term durability for 30 h that is similar to the electrode without bending for OER. The flexible Ni3S2@Ni/CC electrode can be incorporated into wearable electronics and portable water-splitting cells.