Cobalt oxide(Co_(3)O_(4))is currently suitable in energy storage applications because of its high capacity based on the conversion reaction mechanism.However,unmodified Co_(3)O_(4)suffers from distinctly inferior rate...Cobalt oxide(Co_(3)O_(4))is currently suitable in energy storage applications because of its high capacity based on the conversion reaction mechanism.However,unmodified Co_(3)O_(4)suffers from distinctly inferior rate capability and poor cycling stability.On the basis of the aforementioned considerations and density functional theory(DFT)simulations,the three-dimensional hierarchical porous structure(HPS)ultrasmall Co_(3)O_(4)anchored into ionic liquid(IL)modified graphene oxide(GO)has been successfully prepared(ultrasmall/Co_(3)O_(4)-GA-IL).The ultrasmall/Co_(3)O_(4)-GA-IL consists of Co_(3)O_(4)co-assembled with IL modified GO to generate the HPS which can facilitate ion transfer channels through reduction of the electron and ion transportation path and transmission impedance.In addition,N-doping graphene can enhance the inherent electrical conductivity of Co_(3)O_(4),which is proved by the DFT calculations.By virtue of the novel superstructure,the ultrasmall/Co_(3)O_(4)-GA-IL electrode demonstrates a high reversible capacity of 1,304 mAh·g^(−1),an enhanced high-rate capability(715 mAh·g^(−1)at 5 C),and a capacity retention of 98.4%even after 500 cycles at 5 C rate,which corresponds to 0.0003%capacity loss per cycle.Pouch cells based on the cathode are further fabricated and demonstrate excellent mechanical and electrochemical properties under bent and folded state,highlighting the practical application of our deliberately designed electrode in wearable electronics.展开更多
基金National Key Research and Development Program of China(No.2019YFA0705700)the National Natural Science Foundation of China(Nos.51774017 and 51904016)Key Program of Equipment Pre-Research Foundation of China(No.6140721020103)。
文摘Cobalt oxide(Co_(3)O_(4))is currently suitable in energy storage applications because of its high capacity based on the conversion reaction mechanism.However,unmodified Co_(3)O_(4)suffers from distinctly inferior rate capability and poor cycling stability.On the basis of the aforementioned considerations and density functional theory(DFT)simulations,the three-dimensional hierarchical porous structure(HPS)ultrasmall Co_(3)O_(4)anchored into ionic liquid(IL)modified graphene oxide(GO)has been successfully prepared(ultrasmall/Co_(3)O_(4)-GA-IL).The ultrasmall/Co_(3)O_(4)-GA-IL consists of Co_(3)O_(4)co-assembled with IL modified GO to generate the HPS which can facilitate ion transfer channels through reduction of the electron and ion transportation path and transmission impedance.In addition,N-doping graphene can enhance the inherent electrical conductivity of Co_(3)O_(4),which is proved by the DFT calculations.By virtue of the novel superstructure,the ultrasmall/Co_(3)O_(4)-GA-IL electrode demonstrates a high reversible capacity of 1,304 mAh·g^(−1),an enhanced high-rate capability(715 mAh·g^(−1)at 5 C),and a capacity retention of 98.4%even after 500 cycles at 5 C rate,which corresponds to 0.0003%capacity loss per cycle.Pouch cells based on the cathode are further fabricated and demonstrate excellent mechanical and electrochemical properties under bent and folded state,highlighting the practical application of our deliberately designed electrode in wearable electronics.
