Energy harvesting storage hybrid devices have garnered considerable attention as self-rechargeable power sources for wireless and ubiquitous electronics.Triboelectric nanogenerators(TENGs),a common type of energy harv...Energy harvesting storage hybrid devices have garnered considerable attention as self-rechargeable power sources for wireless and ubiquitous electronics.Triboelectric nanogenerators(TENGs),a common type of energy harvester,generate alternating current-based,irregular short pulses,posing a challenge for storing the generated electrical energy in energy storage systems that typically operate with direct current(DC)-based low-frequency response.In this study,we propose a new strategy that leverages high-frequency response to develop efficient chargeable TENG-supercapacitor(SC)hybrid devices.A highfrequency SC was fabricated using hollow-structured MXene electrode materials,resulting in a twofold increase in the charging efficiency of the hybrid device compared to a control SC made with conventional carbon electrode materials.For a systematic understanding,the electrochemical interplay between the TENGs and SCs was investigated as a function of the frequency characteristics of SCs(f_(SC))and the output pulse duration of TENGs(Δt_(TENG)).Increasing the fSC·Δt_(TENG) enhanced the charging efficiency of the TENG-SC hybrid devices.This study highlights the importance of frequency response design in developing efficient chargeable TENG-SC hybrid devices.展开更多
Despite its potential as a high-capacity battery electrode,magnesium(Mg)metals are highly susceptible to electrolytes,resulting in the formation of unwanted passivation layers,which hinder charge transfer phenomena.He...Despite its potential as a high-capacity battery electrode,magnesium(Mg)metals are highly susceptible to electrolytes,resulting in the formation of unwanted passivation layers,which hinder charge transfer phenomena.Here,we first report an anionic covalent organic framework(a-COF)as an electrostatic molecular rectifier(that can preferentially trap solvent molecules)to stabilize Mg metal electrodes.Compared to a neutral COF(n-COF)as a control sample,the a-COF enhances Mg^(2+)transport by facilitating the desolvation of Mg^(2+)-solvent complexes and cationic mobility through its negatively charged one-dimensional columns,thereby achieving an ionic conductivity eight times higher than that of the n-COF.In addition,the anionic porous frameworks in contact with Mg metal electrodes enable a uniform Mg^(2+)flux and interfacial stability with Mg metal electrodes.Consequently,the a-COF exhibited reversible Mg plating/stripping cyclability on Mg metal electrodes compared to the n-COF,demonstrating the electrochemical viability of the anionic frameworks for Mg metal electrode stabilization.展开更多
基金supported by the Basic Science Research Program(RS-2024-00344021 and RS-2023-00261543)through the National Research Foundation of Korea(NRF)grant by the Korean Government(MSIT)the National Research Council of Science&Technology(NST)grant by the Korea Government(MSIT)(GTL24011-000)Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(RS-2024-00420590,HRD Program for Industrial Innovation).
文摘Energy harvesting storage hybrid devices have garnered considerable attention as self-rechargeable power sources for wireless and ubiquitous electronics.Triboelectric nanogenerators(TENGs),a common type of energy harvester,generate alternating current-based,irregular short pulses,posing a challenge for storing the generated electrical energy in energy storage systems that typically operate with direct current(DC)-based low-frequency response.In this study,we propose a new strategy that leverages high-frequency response to develop efficient chargeable TENG-supercapacitor(SC)hybrid devices.A highfrequency SC was fabricated using hollow-structured MXene electrode materials,resulting in a twofold increase in the charging efficiency of the hybrid device compared to a control SC made with conventional carbon electrode materials.For a systematic understanding,the electrochemical interplay between the TENGs and SCs was investigated as a function of the frequency characteristics of SCs(f_(SC))and the output pulse duration of TENGs(Δt_(TENG)).Increasing the fSC·Δt_(TENG) enhanced the charging efficiency of the TENG-SC hybrid devices.This study highlights the importance of frequency response design in developing efficient chargeable TENG-SC hybrid devices.
基金supported by the Technology Innovation Program(grant no.20012216)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)supported by the Basic Science Research Program(grant nos.22021R1A2B5B03001615,2018M3D1A1058744)through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and future Planning.
文摘Despite its potential as a high-capacity battery electrode,magnesium(Mg)metals are highly susceptible to electrolytes,resulting in the formation of unwanted passivation layers,which hinder charge transfer phenomena.Here,we first report an anionic covalent organic framework(a-COF)as an electrostatic molecular rectifier(that can preferentially trap solvent molecules)to stabilize Mg metal electrodes.Compared to a neutral COF(n-COF)as a control sample,the a-COF enhances Mg^(2+)transport by facilitating the desolvation of Mg^(2+)-solvent complexes and cationic mobility through its negatively charged one-dimensional columns,thereby achieving an ionic conductivity eight times higher than that of the n-COF.In addition,the anionic porous frameworks in contact with Mg metal electrodes enable a uniform Mg^(2+)flux and interfacial stability with Mg metal electrodes.Consequently,the a-COF exhibited reversible Mg plating/stripping cyclability on Mg metal electrodes compared to the n-COF,demonstrating the electrochemical viability of the anionic frameworks for Mg metal electrode stabilization.
