Ultrathin porous Mn(PO3)2 nanosheets and MoO2 nanocrystal arrays on N, P-dual-doped graphene for high-energy asymmetric supercapacitors

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 403; p. 126379
• Main Authors: Zhang, Mingmei, Liu, Hong, Ma, Tianjiao, Song, Zixiang, Shao, Shouyan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2021
• Subjects: Graphene-based hybrids; Manganese phosphate; Molybdenum oxide; N, P heteroatom doping; Supercapacitor; Supercapacitor; Molybdenum oxide; Manganese phosphate; Graphene-based hybrids; N, P heteroatom doping
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.126379

•NPG has rich channels and open space surface to provide many active sites.•Mn(PO3)2 porous nanosheets arrayed on N,P-doped graphene enhance the capacitance properties of hybrids.•MoO2 nanoparticles on N,P-doped graphene widen the range of voltage window.•The Mn(PO3)2/NPG//Mn(PO3)2/NPG asymmetric device delivers the high energy density of 96.2 W h kg−1. Recently, heteroatom doped graphene based architectures exhibit promising prospects in the commercial application of supercapacitors because of their higher electrical conductivity and a wider potential window. Herein, we report on ultrathin porous nanosheets Mn(PO3)2 and MoO2 nanocrystal array on N, P dual-doped graphene (NPG) framework and study their supercapacitor properties. The irregularly overhead Mn(PO3)2 present a unique structure, which provide clear electron/ion transport channels to accelerate charge transfer together with the three-dimensional NPG structure. The obtained Mn(PO3)2/NPG hybrid electrode exhibit an extraordinary specific capacity (2073.4F g−1, 1 A g−1) and good rate performance (capacity retention rate of 77.8% from 1 A g−1 to 20 A g−1). In addition, the 3D NPG coated with MoO2 nanocrystal have also made a great progress in electrochemical performance of large capacitance and merely 5.54% fading capacitance after 10,000 cycles. Subsequently, the asymmetric supercapacitor (ASC) hybrid devices based on Mn(PO3)2/NPG as the positive electrode and MoO2/NPG as the negative electrode has a wide voltage range of 0 ~ 1.8 V, delivers an excellent CF value of 213.8F g−1 and keeps 91.5% initial capacitance retention after 10,000 cycles. Furthermore, the as-prepared ASC also obtains an outstanding energy density of 96.2 W h kg−1 at a power performance of 726.73 W kg−1, which demonstrate that the reasonable conductive network of Mn(PO3)2/NPG//MoO2/NPG devices can greatly increase the utilization of active substances, improve the performance in all aspects and open up new avenues of the future application and development of supercapacitors.