CN116825552B - An electrolyte suitable for ultra-low temperature supercapacitors, and a supercapacitor. - Google Patents

An electrolyte suitable for ultra-low temperature supercapacitors, and a supercapacitor.

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CN116825552B
CN116825552B CN202310734692.1A CN202310734692A CN116825552B CN 116825552 B CN116825552 B CN 116825552B CN 202310734692 A CN202310734692 A CN 202310734692A CN 116825552 B CN116825552 B CN 116825552B
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electrolyte
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acetonitrile
supercapacitor
tema
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CN116825552A (en
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杨化超
薄拯
王子凡
祁义恒
陈侠
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Zhejiang University ZJU
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Zhejiang University ZJU
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/54—Electrolytes
    • H01G11/58—Liquid electrolytes
    • H01G11/60—Liquid electrolytes characterised by the solvent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/84—Processes for the manufacture of hybrid or EDL capacitors, or components thereof
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/13—Energy storage using capacitors

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Electric Double-Layer Capacitors Or The Like (AREA)

Abstract

The invention discloses an electrolyte for a super capacitor, which is applicable to ultralow temperature, and comprises a main solvent, a cosolvent and organic salts, wherein the main solvent is acetonitrile, and the cosolvent is selected from 2-pentanone or acetone. The invention also discloses a super capacitor adopting the electrolyte. The electrolyte provided by the invention has higher variable temperature capacity retention rate, higher multiplying power performance, lower impedance characteristic, higher energy density and power density and long cycle life under the low-temperature condition.

Description

Electrolyte for super capacitor suitable for ultralow temperature and super capacitor
Technical Field
The invention relates to the technical field of supercapacitors, in particular to an electrolyte for a supercapacitor and a supercapacitor suitable for ultralow temperature.
Background
The super capacitor has the outstanding advantages of ultra-high power density, ultra-long cycle stability, second-level transient response and the like, and has good application prospect in the aspects of intermittent energy storage such as wind power photovoltaic and the like, power system frequency modulation, heavy machinery potential energy recovery and the like. Supercapacitors are typically composed of electrolyte, electrode pads, separator, and a housing. As one of the most critical components, the electrolyte is usually composed of a solvent and a solute (salt), which determine the core indexes of the supercapacitor, such as the working temperature range, the power density, the energy density, the cycling stability, the transmission impedance and the like, and greatly influence the application and development prospects of the supercapacitor. The Chinese patent publication No. CN115642308A discloses an electrolyte suitable for low temperature and a lithium ion battery comprising the electrolyte, wherein the electrolyte comprises a solvent, a film forming additive and lithium salt, the solvent comprises a nitrile solvent and a carbonate solvent, and the nitrile solvent is any one or more of butyronitrile, isobutyronitrile, valeronitrile and isovaleronitrile. And as disclosed in chinese patent publication No. CN113035586a, a low-temperature flame-retardant organic electrolyte for an electric double layer capacitor and a preparation method thereof are disclosed, the low-temperature flame-retardant organic electrolyte comprises an electrolyte and an organic solvent, the organic solvent comprises a main solvent, a low-temperature cosolvent and a flame-retardant additive, the electrolyte is a quaternary ammonium salt, the main solvent is acetonitrile, and the low-temperature cosolvent is one or a combination of several of carbonate, gamma-butyrolactone, propionate and 1, 3-dioxolane.
The ultra-low temperature application scene is particularly important in various professional fields (for example, the minimum working temperature of an energy storage device is required to reach-60 ℃ in the field of polar scientific investigation, the minimum working temperature of an energy storage device is required to reach-50 ℃ in the field of military equipment, and the minimum working temperature of an energy storage device is required to reach-40 ℃ in the field of electric automobiles). However, current commercial supercapacitors often have difficulty meeting the above application requirements. The electrolyte is formed by dissolving 1mol/L tetraethylammonium tetrafluoroborate (TEA-BF 4) in Acetonitrile (AN) or Propylene Carbonate (PC) solution, wherein the AN solvent and the PC solvent have higher dielectric constants, and the solvation between ions and solvent molecules is stronger, so that the ions are difficult to complete the solvent removal process, thereby bringing higher ion inlet resistance and poorer capacity retention rate and rate capability. In addition, the higher viscosity of PC solvents results in poor molecular dynamics of the electrolyte. Both of the above reasons have led to the minimum operating temperature of commercial supercapacitors being limited to-40 ℃ or higher. Therefore, reasonable choice of the solvent and solute (salt) of the electrolyte will be beneficial to reduce the desolvation energy of ions and reduce the viscosity of the electrolyte, thereby improving the low temperature operating characteristics of the supercapacitor.
Disclosure of Invention
The invention aims to provide an electrolyte for a super capacitor, which is applicable to ultralow temperature and can effectively improve the low-temperature working characteristic of the super capacitor.
The invention provides the following technical scheme:
The electrolyte for the super capacitor comprises a main solvent, a cosolvent and an organic salt, wherein the main solvent is acetonitrile, and the cosolvent is selected from 2-pentanone or acetone.
In the electrolyte provided by the invention, acetonitrile with a high dielectric constant is used as a main solvent and is responsible for promoting ion dissociation so as to improve solution conductivity, and one solvent of 2-pentanone and acetone with different dielectric constants is used as a cosolvent. The electrolyte based on the acetone/2-pentanone system (medium dielectric constant) has lower ion desolvation energy and lower viscosity, so that the electrolyte has higher variable temperature capacity retention rate, higher multiplying power performance, lower impedance characteristic, higher energy density, higher power density and longer cycle life under the low-temperature condition, can effectively improve the low-temperature working characteristic of the supercapacitor, and has low-temperature energy storage application potential.
The volume ratio of the main solvent to the cosolvent is (0.5-4): 1, and the electrolyte has smaller impedance characteristic under the proportion of the main solvent to the cosolvent. The super capacitor assembled based on the electrolyte has high capacity retention exceeding 65% at a scanning rate of 100mV/s by cyclic voltammetry.
The organic salt is selected from triethylmethyl ammonium tetrafluoroborate TEMA-BF 4.
The concentration of the organic salt in the electrolyte is 0.5-1mol/L.
The lower limit of the working temperature of the electrolyte is-70 ℃.
Preferably, the cosolvent is acetone, the volume ratio of the main solvent to the cosolvent is (0.5-4): 1, and the electrolyte simultaneously shows excellent capacitance retention rate, excellent energy density and power density and low-temperature cycle performance.
Further preferably, the electrolyte is TEMA-BF 4 - (acetonitrile/acetone (1:1)): the super capacitor of the electrolyte shows excellent capacitor retention rate (the capacitor retention rate is 89% after the temperature is reduced from 20 ℃ to-70 ℃ under the sweep speed of 10mV/s in cyclic voltammetry test), the super capacitor of the electrolyte respectively reaches 22.28Wh/kg high energy density under 141.22W/kg power density and 6849.35W/kg high power density under 11.79Wh/kg energy density, and the super capacitor of the electrolyte can reach 94.1% of capacitor retention rate after 30000 times of cycles under the constant current charge-discharge test with the current density of 5A/g under the environment of-70 ℃ and has ultra-long cycle stability.
The preparation method of the electrolyte comprises the steps of mixing a cosolvent and a main solvent under the room temperature environment with absolute pressure of 101-110kPa and isolation of oxygen and water to form a homogeneous solvent, and then adding organic salt.
Specifically, one of 2-pentanone (MPK, dielectric constant epsilon=15.4) and acetone (ACT, dielectric constant epsilon=21.4) with a purity of 99.0% or more is mixed with acetonitrile (purity of 99.0% or more), which is a main solvent capable of promoting ion dissociation and thus improving solution conductivity, in the above proportions, under the room temperature environment (oxygen of 1ppm or less and water of 1ppm or less) isolated from oxygen and water under the absolute pressure of 101-110kPa until a clear and transparent homogeneous solvent (denoted acetonitrile/X (y: 1), wherein y represents the proportion of the main solvent and X represents one of the above cosolvents) is formed. Then adding the TEMA-BF 4 salt with the concentration into the binary solvent to obtain the electrolyte for the super capacitor, wherein the electrolyte is named as TEMA-BF 4 - (acetonitrile/X (y: 1)). The electrolyte is stored in a sealed manner in a room temperature environment which is isolated from oxygen and water.
The invention also provides a super capacitor adopting the electrolyte.
Compared with the prior art, the invention has the following advantages:
1. The electrolyte system provided by the invention has extremely low lower limit (-70 ℃) of working temperature, and the super capacitor of the electrolyte shows excellent capacitor retention rate.
2. The electrolyte system provided by the invention has excellent energy density and power density at-70 ℃.
3. The electrolyte system provided by the invention has excellent low-temperature cycle performance at-70 ℃.
Drawings
FIG. 1 is a cyclic voltammetry test curve of a supercapacitor of example 1 based on a TEMA-BF 4 - (acetonitrile/acetone (1:1)) electrolyte at 20 and-70℃at a sweep rate of 100 mV/s.
FIG. 2 is a plot of cyclic voltammetry test at-70℃at 10, 50, 100mV/s sweep rate for the supercapacitor of example 1 based on TEMA-BF 4 - (acetonitrile/acetone (1:1)) electrolyte.
FIG. 3 is an electrochemical impedance spectrum of the supercapacitor of example 1 based on a TEMA-BF 4 - (acetonitrile/acetone (1:1)) electrolyte at 20 and-70 ℃.
FIG. 4 is a graph of capacitance retention and coulombic efficiency for a supercapacitor based on TEMA-BF 4 - (acetonitrile/acetone (1:1)) electrolyte at-70℃for a 30000-cycle in example 1.
FIG. 5 is an energy density-power density curve for the super capacitor of example 1 based on TEMA-BF 4 - (acetonitrile/acetone (1:1)) electrolyte at-60℃and-70℃respectively.
FIG. 6 is a cyclic voltammetric test curve for a supercapacitor based on a TEMA-BF 4 - (acetonitrile/acetone (0.5:1)) electrolyte in example 2 at 20 and-70℃at a scan rate of 100 mV/s.
FIG. 7 is a cyclic voltammetry test curve of a supercapacitor of example 3 based on a TEMA-BF 4 - (acetonitrile/acetone (4:1)) electrolyte at 20 and-70℃at a sweep rate of 100 mV/s.
FIG. 8 is a cyclic voltammetric test curve for a supercapacitor based on the electrolyte of TEMA-BF 4 - (acetonitrile/2-pentanone (1:1)) in example 4 at 20 and-70℃at a sweep rate of 100 mV/s.
FIG. 9 is an electrochemical impedance spectrum of the supercapacitor of example 4 based on the electrolyte of TEMA-BF 4 - (acetonitrile/2-pentanone (1:1)) at 20 and-70 ℃.
FIG. 10 is a cyclic voltammetry test curve for a supercapacitor based on TEMA-BF 4 - (acetonitrile/dioxolane) electrolyte at 20 and-70℃and a sweep rate of 100mV/s in comparative example 1.
FIG. 11 is a graph of electrochemical impedance spectra of a TEMA-BF 4 - (acetonitrile/dioxolane) electrolyte-based supercapacitor of comparative example 1 at 20 and-70 ℃.
FIG. 12 is a cyclic voltammetry test curve for a TEMA-BF 4 - (acetonitrile/propylene carbonate) electrolyte based supercapacitor of comparative example 2 at 20 and-70℃at a sweep rate of 100 mV/s.
FIG. 13 is a graph of electrochemical impedance spectra of a TEMA-BF 4 - (acetonitrile/propylene carbonate) electrolyte-based supercapacitor of comparative example 2 at 20 and-70 ℃.
Detailed Description
In order to more particularly describe the present invention, the following detailed description of the technical scheme of the present invention is provided with reference to the accompanying drawings and the specific embodiments. It should be understood that these descriptions are merely provided to further illustrate the features and advantages of the present invention and are not intended to limit the scope of the claims.
Example 1
Co-solvent acetone (ACT, epsilon=21.4, purity: 99.0%) with medium dielectric constant is mixed with main solvent acetonitrile (purity: 99.0%) capable of promoting ion dissociation to improve solution conductivity according to a volume ratio of 1:1 at room temperature environment (oxygen: 1ppm, water: 1 ppm) isolated from oxygen and water at absolute pressure of 101-110kPa until clear and transparent homogeneous solvent (denoted acetonitrile/acetone (1:1)) is formed. Then, 0.5M of TEMA-BF 4 salt was added to the binary solvent to obtain an electrolyte for a supercapacitor, which was designated as TEMA-BF 4 - (acetonitrile/acetone (1:1)). The electrolyte is stored in a sealed manner in a room temperature environment which is isolated from oxygen and water.
When the TEMA-BF 4 - (acetonitrile/acetone (1:1)) electrolyte obtained in this example was used in a supercapacitor (using a symmetric commercial YP-50 activated carbon electrode), the acetone molecules (medium dielectric constant, epsilon=21.4) and the weak solvation structure formed by the ions in the electrolyte would bring about lower ion desolvation energy and smaller entrance impedance, and the lower viscosity (0.316 mpa·s) would bring about faster molecular dynamics, so that the temperature-change capacity retention rate, low-temperature rate performance and impedance characteristics are all excellent. When the temperature was reduced from 20 ℃ to-70 ℃, the cyclic voltammogram of the supercapacitor based on TEMA-BF 4 - (acetonitrile/acetone (1:1)) electrolyte remained rectangular, with a capacity retention up to 76% (fig. 1), indicating excellent capacity retention of the supercapacitor, even at high sweep rates of cyclic voltammogram 100 mV/s. Cyclic voltammograms were tested at different scan rates at-70 ℃ as shown in figure 2. The results of 88.1% (19.3F/g) and 78.3% (16.9F/g) of the specific capacitance reduced to 10mV/s at the sweeping speeds of 50 mV/s and 100mV/s respectively show that the super capacitor has excellent multiplying power performance. The impedance of the electrolyte at-70 ℃ is only 4.52 omega, and the charge transfer impedance is only 3.35 omega (figure 3), indicating the lower impedance characteristics of the supercapacitor. The supercapacitor capacity retention after a 30000-cycle long-cycle test at-70 ℃ was 94.1% (fig. 4). The supercapacitor had a high energy density of 22.28Wh/kg at 141.22W/kg and 6849.35W/kg at 11.79Wh/kg, respectively (FIG. 5). In summary, the acetone-based electrolyte exhibits good low-temperature electrochemical properties.
Example 2
Co-solvent acetone (ACT, epsilon=21.4, purity: 99.0%) with medium dielectric constant was mixed with main solvent acetonitrile (purity: 99.0%) that promotes ion dissociation to increase solution conductivity at a volume ratio of 0.5:1 at room temperature (oxygen: 1ppm, water: 1 ppm) isolated from oxygen and water at absolute pressure of 101-110kPa until a clear transparent homogeneous solvent (denoted acetonitrile/acetone (0.5:1)) was formed. Then, 0.5M of TEMA-BF 4 salt was added to the binary solvent to obtain an electrolyte for a supercapacitor, which was designated as TEMA-BF 4 - (acetonitrile/acetone (0.5:1)). The electrolyte is stored in a sealed manner in a room temperature environment which is isolated from oxygen and water.
When the TEMA-BF 4 - (acetonitrile/acetone) electrolyte obtained in this example was used in a supercapacitor (using a symmetric commercial YP-50 activated carbon electrode), the low solvation structure formed by acetone molecules (medium dielectric constant, epsilon=21.4) and ions in the electrolyte resulted in lower ion desolvation energy and smaller entrance impedance, and the lower viscosity (0.316 mpa·s) resulted in faster molecular dynamics, so that the temperature change capacity retention rate, low temperature rate performance and impedance characteristics were all excellent. When the temperature was reduced from 20 ℃ to-70 ℃, the cyclic voltammogram of the supercapacitor based on TEMA-BF 4 - (acetonitrile/acetone (0.5:1)) electrolyte remained rectangular, with a capacity retention up to 73% (fig. 6), indicating excellent capacity retention of the supercapacitor, even at high sweep rates of cyclic voltammogram 100 mV/s.
Example 3
Co-solvent acetone (ACT, epsilon=21.4, purity: 99.0%) with medium dielectric constant is mixed with main solvent acetonitrile (purity: 99.0%) capable of promoting ion dissociation to improve solution conductivity according to a volume ratio of 4:1 at room temperature environment (oxygen: 1ppm or less and water: 1ppm or less) with absolute pressure of 101-110kPa and isolation of oxygen and water until clear and transparent homogeneous solvent (denoted acetonitrile/acetone (4:1)) is formed. Then, 0.5M of TEMA-BF 4 salt was added to the binary solvent to obtain an electrolyte for a supercapacitor, which was designated as TEMA-BF 4 - (acetonitrile/acetone (4:1)). The electrolyte is stored in a sealed manner in a room temperature environment which is isolated from oxygen and water.
When the TEMA-BF 4 - (acetonitrile/acetone) electrolyte obtained in this example was used in a supercapacitor (using a symmetric commercial YP-50 activated carbon electrode), the low solvation structure formed by acetone molecules (medium dielectric constant, epsilon=21.4) and ions in the electrolyte resulted in lower ion desolvation energy and smaller entrance impedance, and the lower viscosity (0.316 mpa·s) resulted in faster molecular dynamics, so that the temperature change capacity retention rate, low temperature rate performance and impedance characteristics were all excellent. The cyclic voltammogram of a supercapacitor based on TEMA-BF 4 - (acetonitrile/acetone (4:1)) electrolyte remained rectangular, with a capacity retention as high as 68% (fig. 7), even at high sweep rates of cyclic voltammogram 100mV/s, when the temperature was reduced from 20 ℃ to-70 ℃.
Example 4
The cosolvent 2-pentanone (MPK, epsilon=7.3, purity not less than 99.0%) with low dielectric constant is mixed with the main solvent acetonitrile (purity not less than 99.0%) capable of promoting ion dissociation to improve solution conductivity in the above ratio under room temperature environment (oxygen not more than 1ppm, water not more than 1 ppm) with absolute pressure of 101-110kPa, oxygen and water isolated until a clear and transparent homogeneous solvent (denoted as acetonitrile/2-pentanone (1:1)) is formed. Then, 0.5M of TEMA-BF 4 salt was added to the binary solvent to obtain an electrolyte for a supercapacitor, which was designated as TEMA-BF 4 - (acetonitrile/2-pentanone (1:1)). The electrolyte is stored in a sealed manner in a room temperature environment which is isolated from oxygen and water.
When the TEMA-BF 4 - (acetonitrile/2-pentanone (1:1)) electrolyte obtained in this example was used in a supercapacitor (using a symmetric commercial YP-50 activated carbon electrode), the 2-pentanone molecules (low dielectric constant, epsilon=15.4) in the electrolyte did not participate in the ion solvation structure, which resulted in higher ion desolvation energy and higher access impedance, and therefore, the temperature change capacity retention rate, low temperature rate performance and impedance characteristics were poor. Capacity retention at 60 ℃ versus 20 ℃ was only 50.4% (fig. 8). The electrolyte impedance is as high as 8.32Ω and the charge transfer impedance is as high as 8.58Ω at-60 ℃ (fig. 9). In conclusion, 2-pentanone based electrolytes exhibit poor low temperature electrochemical properties.
Comparative example 1
The cosolvent dioxolane (DIOX, epsilon=7.3, purity > 99.0%) with low dielectric constant is mixed with the main solvent acetonitrile (purity > 99.0%) that promotes ion dissociation to increase solution conductivity in the above proportions at room temperature (oxygen < 1ppm, water < 1 ppm) with absolute pressure 101-110kPa, oxygen and water exclusion until a clear transparent homogeneous solvent (denoted acetonitrile/dioxolane) is formed. Then, 0.5M of TEMA-BF 4 salt was added to the binary solvent to obtain an electrolyte for a supercapacitor, which was designated as TEMA-BF 4 - (acetonitrile/dioxolane). The electrolyte is stored in a sealed manner in a room temperature environment which is isolated from oxygen and water.
When the TEMA-BF 4 - (acetonitrile/dioxolane) electrolyte obtained in this comparative example is used in a supercapacitor (using a symmetric commercial YP-50 activated carbon electrode), the dioxolane molecules (low dielectric constant, epsilon=7.3) in the electrolyte do not participate in the ion solvation structure, which results in higher ion desolvation energy and higher entrance impedance, so that the temperature-change capacity retention rate, low-temperature rate performance and impedance characteristics are poor. The capacity retention at-60 ℃ relative to 20 ℃ was only 43.1% (fig. 10). The electrolyte impedance is as high as 8.03 Ω and the charge transfer impedance is as high as 8.53 Ω at-60 ℃ (fig. 11). In summary, dioxolane-based electrolytes exhibit poor low temperature electrochemical properties.
Comparative example 2
Propylene carbonate (PC, epsilon=64.9, purity is more than or equal to 99.0%) which is a cosolvent with a high dielectric constant is mixed with acetonitrile (purity is more than or equal to 99.0%) which is a main solvent capable of promoting ion dissociation so as to improve solution conductivity according to the proportion, and the mixture is subjected to room temperature environment (oxygen is less than or equal to 1ppm and water is less than or equal to 1 ppm) under the absolute pressure of 101-110kPa and isolated from oxygen and water until a clear and transparent homogeneous solvent (which is denoted as acetonitrile/propylene carbonate) is formed, and then TEMA-BF 4 salt with the concentration of 0.5M is added into the binary solvent to obtain the electrolyte for the super capacitor, which is denoted as TEMA-BF 4 - (acetonitrile/propylene carbonate). The electrolyte is stored in a sealed manner in a room temperature environment which is isolated from oxygen and water.
When the TEMA-BF 4 - (acetonitrile/propylene carbonate) electrolyte obtained in this comparative example is used in a supercapacitor (using a symmetric commercial YP-50 activated carbon electrode), the propylene carbonate molecules (high dielectric constant, epsilon=64.9) in the electrolyte and the ions form a strong solvation structure, which results in higher ion desolvation energy and higher entrance impedance, so that the temperature-change capacity retention rate, low-temperature rate performance and impedance characteristics are poor. The capacity retention at-60 ℃ versus 20 ℃ was only 40.8% (fig. 12). The electrolyte impedance is as high as 10.12 Ω and the charge transfer impedance is as high as 9.52 Ω at-60 ℃ (fig. 13). In summary, propylene carbonate-based electrolytes exhibit poor low temperature electrochemical properties.
The foregoing examples are merely exemplary embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the invention. It should be noted that modifications and improvements can be made by those skilled in the art without departing from the spirit of the invention, and these alternatives fall within the scope of the invention.

Claims (4)

1.一种适用于超低温的超级电容器用电解液，其特征在于，所述电解液包括主溶剂、共溶剂和有机盐，所述主溶剂为乙腈，所述共溶剂为丙酮；1. An electrolyte for supercapacitors suitable for ultra-low temperature applications, characterized in that the electrolyte comprises a main solvent, a co-solvent, and an organic salt, wherein the main solvent is acetonitrile, and the co-solvent is acetone; 所述主溶剂和共溶剂的体积比为1：1；The volume ratio of the main solvent to the co-solvent is 1:1; 所述有机盐选自三乙基甲基铵四氟硼酸盐TEMA-BF4；所述电解液中有机盐的浓度为0.5mol/L。The organic salt is selected from triethylmethylammonium tetrafluoroborate (TEMA-BF4 ) ; the concentration of the organic salt in the electrolyte is 0.5 mol/L. 2.根据权利要求1所述的适用于超低温的超级电容器用电解液，其特征在于，所述电解液的工作温度下限为-70℃。2. The electrolyte for supercapacitors suitable for ultra-low temperatures according to claim 1, characterized in that the lower limit of the working temperature of the electrolyte is -70℃. 3.根据权利要求1-2任一所述的适用于超低温的超级电容器用电解液，其特征在于，所述电解液的制备方法为：将共溶剂和主溶剂在绝对压力101-110kPa、隔绝氧气和水的室温环境下混合，形成均相溶剂后加入有机盐。3. The electrolyte for supercapacitors suitable for ultra-low temperature applications according to any one of claims 1-2, characterized in that the preparation method of the electrolyte is as follows: mixing the co-solvent and the main solvent at an absolute pressure of 101-110 kPa and at room temperature in the absence of oxygen and water to form a homogeneous solvent, and then adding an organic salt. 4.一种超级电容器，其特征在于，采用权利要求1-2任一所述的电解液。4. A supercapacitor, characterized in that it uses the electrolyte described in any one of claims 1-2.
CN202310734692.1A 2023-06-20 2023-06-20 An electrolyte suitable for ultra-low temperature supercapacitors, and a supercapacitor. Active CN116825552B (en)

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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1489773A (en) * 2001-01-30 2004-04-14 ���տ�˹�ɷ����޹�˾ Electrolyte solutions for electrochemical components

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006165307A (en) * 2004-12-08 2006-06-22 Mitsubishi Gas Chem Co Inc Electric double layer capacitor
WO2008041714A1 (en) * 2006-10-03 2008-04-10 Ube Industries, Ltd. Charging device, and its manufacturing method
CN102280664B (en) * 2010-06-09 2015-07-22 中国科学院物理研究所 Electrolyte and secondary lithium battery and capacitor containing electrolyte

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1489773A (en) * 2001-01-30 2004-04-14 ���տ�˹�ɷ����޹�˾ Electrolyte solutions for electrochemical components

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Beyond Simple Dilution: Superior Conductivities from Cosolvation of Acetonitrile/LiTFSI Concentrated Solution with Acetone;Murillo L. Martins等;《J. Phys. Chem. C》;20220126;第2788-2796页 *

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