High-energy sodium-ion hybrid capacitors through nanograin-boundary-induced pseudocapacitance of Co_(3)O_(4) nanorods

作     者：Wenliang Feng Venkata Sai Avvaru Steven JHinder Vinodkumar Etacheri Wenliang Feng;Venkata Sai Avvaru;Steven J.Hinder;Vinodkumar Etacheri

作者机构：IMDEA Materials InstituteC/Eric Kandel 2GetafeMadrid 28906Spain Universidad Politécnica de MadridE.T.S.de Ingenieros de Caminos28040 MadridSpain Universidad Autónoma de MadridC/Francisco Tomás y Valiente728049 MadridSpain Surface Analysis LaboratoryFaculty of Engineering and Physical Sciences University of Surrey GuildfordSurrey GU27XHUnited Kingdom 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2022年第31卷第6期

页      面：338-346,I0009页

核心收录：

学科分类：081702[工学-化学工艺] 080801[工学-电机与电器] 0808[工学-电气工程] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0817[工学-化学工程与技术] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：financially supported by the IMDEA Materials Institute STRUBAT Project, Spanish Ministry of Economy, Industry, and Competitiveness (MINECO), the Spanish Ministry of Science and Innovation, and Comunidad de Madrid for Juan de la Cierva fellowship (IJCI-2015-25488) the Retos Investigacion Project (MAT2017-84002-C2-2-R)/Ramon y Cajal fellowship (RYC-2018-025893-I) the Talent attraction fellowship (2016-T1/IND-1300) the China Scholarship Council (201706740087) 

主　　题：Sodium-ion hybrid capacitor Cobalt oxide nanorod Nanograin-boundary Pseudocapacitance 

摘      要：Sodium-ion hybrid capacitors (SICs) have been proposed to bridge performance gaps between batteries and supercapacitors,and thus realize both high energy density and power density in a single ***,applications of SICs are severely restricted by their insufficient energy densities (100Wh/kg) resulted from the kinetics imbalance between cathodes and ***,we report a nanograin-boundary-rich hierarchical Co_(3)O_(4) nanorod anode composed of~20 nm *** pseudocapacitance (up to 72%@1.0 mV/s) is achieved through nanograin-boundary-induced pseudocapacitive-type Na^(+) storage ***_(3)O_(4) nanorod anode delivers in this case highly reversible capacity (810 mAh/g@0.025 A/g),excellent rate capability (335 mAh/g@5.0 A/g),and improved cycle stability (100 cycles@1.0 A/g with negligible capacity degradation).The outstanding performance can be credited to the hierarchical morphology of Co_(3)O_(4) nanorods and the well-designed nanograinboundaries between nanocrystallites that avoid particle agglomeration,induce pseudocapacitive-type Na^(+) storage,and accommodate volume variation during sodiation-desodiation *** of the Co_(3)O_(4) nanorods not only generates defects for extra surficial Na^(+) storage but also increases the electronic conductivity for efficient charge separation and lowers energy barrier for Na^(+) *** of conventional reaction mechanism and pseudocapacitive-type Na^(+) storage enables high specific capacity,rapid Na^(+) diffusion,and improved structural stability of the Co_(3)O_(4) nanorod *** SIC integrating this highly pseudocapacitive anode and activated carbon cathode delivers exceptional energy density (175 Wh/kg@40 W/kg),power density (6632 W/kg@37 Wh/kg),cycle life (6000 cycles@1.0 A/g with a capacity retention of 81%),and coulombic efficiency (~100%).