Tailoring NH_(4)^(+)storage by regulating oxygen defect in ammonium vanadate  

作　　者：Yanyan Liu Ziyi Feng Hanmei Jiang Xueying Dong Changgong Meng Yifu Zhang 

机构地区：[1]State Key Laboratory of Fine Chemicals,School of Chemical Engineering,Dalian University of Technology,Dalian,116024,China [2]College of Environmental and Chemical Engineering,Dalian University,Dalian,116622,China

出　　处：《Green Energy & Environment》2024年第7期1171-1182,共12页绿色能源与环境（英文版）

基　　金：partially supported by the Large Instrument and Equipment Open Foundation of Dalian University of Technology and Fundamental Research Funds for the Central Universities(DUT21LK34)。

摘　　要：Defect engineering is an effective strategy for modifying the energy storage materials to improve their electrochemical performance.However,the impact of oxygen defect and its content on the electrochemical performances in the burgeoning aqueous NH_(4)^(+)storage field remains explored.Therefore,for the first time in this work,an oxygen-defective ammonium vanadate[(NH_(4))_(2)V_(10)O_(25)·8H_(2)O,denoted as Od-NHVO]with a novel 3D porous flower-like architecture was achieved via the reduction of thiourea in a mild reaction condition,which is a facile method that can realize the intention to regulate the oxygen defect content,with the capability of mass-production.The as-prepared Od_M-NHVO with moderate oxygen defect content can deliver a stable specific capacitance output(505 F g^(-1),252 mAh g^(-1)at 0.5 A g^(-1)with~80% capacitance retention after 10,000 cycles),which benefits from extra active sites,unimpeded NH_(4)^(+)-migration path and relatively high structure integrity.In contrast,low oxygen defect content will lead to the torpid electrochemical reaction kinetics while too high content of it will reduce the chargestorage capability and induce structural disintegration.The superior NH_(4)^(+)-storage behavior is achieved with the reversible intercalation/deintercalation process of NH_(4)^(+)accompanied by forming/breaking of hydrogen bond.As expected,the assembled flexible OdM-NHVO//PTCDI quasi-solid-state hybrid supercapacitor(FQSS HSC)also exhibits high areal capacitance,energy density and reliable flexibility.This work provides a new avenue for developing materials with oxygen-deficient structure for application in various aqueous non-metal cation storage systems.

关 键 词：Ammonium vanadate Oxygen defect Ammonium-ion storage Hybrid supercapacitors Electrochemical performance 

分 类 号：TM53[电气工程—电器]