Zn2SiO4@C submicro-ellipsoids assembled from oriented nanorods with outstanding rate performance for Li-ion capacitors. Issue 34 (11th August 2022)

• Record Type: Journal Article
• Authors: Cheng, Fei; Zhu, Chengyu; Zhang, Yanan; Ye, Youwen; Li, Huanrong; Lu, An-Hui
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 34(2022)
• Page Start: 17561
• Page End: 17571
• Publication Date: 2022-08-11
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2ta03993a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A Zn2 SiO4 @C network with fast charge transfer kinetics assembled from submicro-ellipsoids containing uniformly aligned nanorods is designed and prepared. The assembled Zn2 SiO4 @C//graphene hydrogel LIC exhibits excellent electrochemical properties. Abstract : Lithium-ion capacitors (LICs), as a highly potential energy converter, integrate the advantages of supercapacitors and batteries and can provide a balanced output of energy and power density. However, the tardy dynamics of the battery-type anode usually results in the sacrifice of power or energy density. Herein, a highly conductive Zn2 SiO4 @C network assembled from uniform submicro-ellipsoids is designed and prepared, in which the short nanorods are oriented and closely arranged and the nitrogen-doped carbon permeated into the whole submicro-ellipsoid. This rectilinear, ordered and multipath charge transfer mode in the Zn2 SiO4 @C hybrid ensures a rapid electrochemical kinetics, leading to a remarkable specific capacity of 1746 mA h g −1 at 0.2 A g −1 over 500 cycles, and a superior capacity ratio of 71% even at 5 A g −1 (compared with the reversible capacity at 0.2 A g −1 ). The LIC assembled using the Zn2 SiO4 @C anode and graphene hydrogel cathode shows an outstanding energy density of 215 W h kg −1 at 196 W kg −1 . Even at an ultra-high power density of 9999 W kg −1, the energy density remains at 79 W h kg −1 . The rational and optimal construction of micro-/nano-structured ellipsoid materials provides a new path for the design and synthesis of high-energy and high-power LICs.