Solid-state and quasi-solid-state electrolytes have been attracting the scientific community’s attention in the last decade. These electrolytes provide significant advantages, such as the absence of leakage and separ...Solid-state and quasi-solid-state electrolytes have been attracting the scientific community’s attention in the last decade. These electrolytes provide significant advantages, such as the absence of leakage and separators for devices and safety for users. They also allow the assembly of stretchable and bendable supercapacitors. Comparing solid-state to quasi-solid-states, the last provides the most significant energy and power densities due to the better ionic conductivity. Our goal here is to present recent advances on quasisolid-state electrolytes, including gel-polymer electrolytes. We reviewed the most recent literature on quasi-solid-state electrolytes with different solvents for supercapacitors. Organic quasi-solid-state electrolytes need greater attention once they reach an excellent working voltage window greater than 2.5 V.Meanwhile, aqueous-based solid-state electrolytes have a restricted voltage window to less than 2 V. On the other hand, they are easier to handle, provide greater ionic conductivity and capacitance. Recent water-in-salt polymer-electrolytes have shown stability as great as 2 V encouraging further development in aqueous-based quasi-solid-state electrolytes. Moreover, hydrophilic conductive polymers have great commercial appeal for bendable devices. Thus, these electrolytes can be employed in flexible and bendable devices, favoring the improvement of portable electronics and wearable devices(376 references were evaluated and summarized here).展开更多
Electrical double-layer capacitors(EDLCs)consist of energy storage devices that present high-power and moderate energy density.The electrolyte and electrode physicochemical properties are crucial for improving their o...Electrical double-layer capacitors(EDLCs)consist of energy storage devices that present high-power and moderate energy density.The electrolyte and electrode physicochemical properties are crucial for improving their overall energy storage capabilities.Therefore,the stability of the EDLCs’materials is the primary focus of this study.Since energy storage depends on the specific capacitance,and also on the square of the maximum capacitive cell voltage(UMCV).Thus,electrodes with high specific surface area(SSA)and electrolytes with excellent electrochemical stability are commonly reported in the literature.Aqueous electrolytes are safer and green devices compared to other organic-based solutions.On the other hand,their UMCVis reduced compared to other electrolytes(e.g.,organic-based and ionic liquids).In this sense,spanning the UMCVfor aqueous-based electrolytes is a’hot topic’research.Unfortunately,the lack of protocols to establish reliable UMCVvalues has culminated in the publishing of several conflicting results.Herein,we confirm that multiwalled carbon nanotubes(MWCNTs)housed in cells degrade and produce CO_(2) under abusive polarisation conditions.It is probed by employing electrochemical techniques,in-situ FTIR and in-situ Raman spectroscopies.From these considerations,the current study uses spectro-electrochemical techniques to support the correct determination of the electrode and electrolyte stability conditions as a function of the operating electrochemical parameters.展开更多
基金the funding agencies FAPESP(2014/02163-7,2017/11958-1,2020/14968-0)and CNPq(PQ-2 grant:Process 131234/2020-0&310544/2019-0)the funding from Shell and the importance of the support provided by the ANP(Brazil’s National Oil,Natural Gas,and Biofuels Agency)by the R&D levy regulation。
文摘Solid-state and quasi-solid-state electrolytes have been attracting the scientific community’s attention in the last decade. These electrolytes provide significant advantages, such as the absence of leakage and separators for devices and safety for users. They also allow the assembly of stretchable and bendable supercapacitors. Comparing solid-state to quasi-solid-states, the last provides the most significant energy and power densities due to the better ionic conductivity. Our goal here is to present recent advances on quasisolid-state electrolytes, including gel-polymer electrolytes. We reviewed the most recent literature on quasi-solid-state electrolytes with different solvents for supercapacitors. Organic quasi-solid-state electrolytes need greater attention once they reach an excellent working voltage window greater than 2.5 V.Meanwhile, aqueous-based solid-state electrolytes have a restricted voltage window to less than 2 V. On the other hand, they are easier to handle, provide greater ionic conductivity and capacitance. Recent water-in-salt polymer-electrolytes have shown stability as great as 2 V encouraging further development in aqueous-based quasi-solid-state electrolytes. Moreover, hydrophilic conductive polymers have great commercial appeal for bendable devices. Thus, these electrolytes can be employed in flexible and bendable devices, favoring the improvement of portable electronics and wearable devices(376 references were evaluated and summarized here).
基金the financial support from the Brazilian funding agencies CNPq(301486/2016-6)FAEPEX(2426/17)+7 种基金FAPESP(2020/04431-0,2020/04281-8,2016/25082-8,2017/11986-5,2017/11958-1,2014/02163-7,2018/20756-6,2018/02713-8)CAPES(1740195)the financial support from CNPq(Processes 131234/2020-0 and 130741/2021-3)the Fundação ao AmparoàPesquisa do Estado de Minas Gerais(FAPEMIGCNPq for the PQ-2 grant(Process 310544/20190)the support of Shell,the strategic importance of the support given by Brazil’s National Oil,Natural Gas,and Biofuels Agency(ANP)through the R&D levy regulationthe Center for Innovation on New Energies(CINE)the LNLS/CNPEM。
文摘Electrical double-layer capacitors(EDLCs)consist of energy storage devices that present high-power and moderate energy density.The electrolyte and electrode physicochemical properties are crucial for improving their overall energy storage capabilities.Therefore,the stability of the EDLCs’materials is the primary focus of this study.Since energy storage depends on the specific capacitance,and also on the square of the maximum capacitive cell voltage(UMCV).Thus,electrodes with high specific surface area(SSA)and electrolytes with excellent electrochemical stability are commonly reported in the literature.Aqueous electrolytes are safer and green devices compared to other organic-based solutions.On the other hand,their UMCVis reduced compared to other electrolytes(e.g.,organic-based and ionic liquids).In this sense,spanning the UMCVfor aqueous-based electrolytes is a’hot topic’research.Unfortunately,the lack of protocols to establish reliable UMCVvalues has culminated in the publishing of several conflicting results.Herein,we confirm that multiwalled carbon nanotubes(MWCNTs)housed in cells degrade and produce CO_(2) under abusive polarisation conditions.It is probed by employing electrochemical techniques,in-situ FTIR and in-situ Raman spectroscopies.From these considerations,the current study uses spectro-electrochemical techniques to support the correct determination of the electrode and electrolyte stability conditions as a function of the operating electrochemical parameters.
