JP2019522369A - Self-charging and / or self-cycling electrochemical cell - Google Patents

Abstract

The present disclosure provides an electrochemical cell comprising a solid glass electrolyte comprising alkali metal working ions and bipolar molecules conducted by an electrolyte, an anode having an effective anode chemical potential μA, and a cathode having an effective cathode chemical potential μC. . One or both of the cathode and anode are substantially devoid of working ions prior to the initial charge or discharge of the electrochemical cell. In open circuit prior to initial charge or discharge, due to the difference between μA and μC at one or both of the interface between the solid glass electrolyte and the anode and the interface between the solid glass electrolyte and the cathode. Thus, an electric double layer capacitor is formed.

Description

TECHNICAL FIELD The present disclosure relates to self-charging and / or self-cycling electrochemical cells that include solid glass electrolytes.

BACKGROUND An electrochemical cell has two electrodes, an anode and a cathode, separated by an electrolyte. In conventional electrochemical cells, these electrode materials are both electronically and chemically active. The anode is a chemical reductant and the cathode is a chemical oxidant. Both the anode and the cathode can obtain and lose ions referred to as battery working ions, typically the same ions. The electrolyte is a conductor of working ions, but normally the electrolyte cannot gain and lose ions. The electrolyte is an electronic insulator and does not move electrons within the battery. In conventional electrochemical cells, both or at least one of the anode and cathode contain working ions prior to cycling of the electrochemical cell.

  An electrochemical cell operates through a reaction between two electrodes having electronic and ionic components. The electrolyte conducts working ions inside the cell and allows electrons (which are also involved in the reaction) to pass through an external circuit.

  The battery may be a single electrochemical cell, and the battery may be a combination of multiple electrochemical cells.

SUMMARY The present disclosure includes an alkali metal working ions and dipoles are conducted by an electrolyte (a dipole), a solid glass electrolyte, an anode having an effective anode chemical potential mu _A, a cathode having an effective cathode chemical potential mu _C An electrochemical cell is provided. One or both of the cathode and anode are substantially devoid of working ions prior to the initial charge or discharge of the electrochemical cell. In an open circuit prior to initial charge or discharge, the difference between μ _A and μ _C at one or both of the interface between the solid glass electrolyte and the anode and the interface between the solid glass electrolyte and the cathode As a result, an electric double layer capacitor is formed.

The electrochemical cell may have a combination of any or all of the following additional features unless such features are clearly mutually exclusive: a) at least one or both of the cathode and anode B) at least one or both of the cathode and anode may consist essentially of metal or may consist of metal; c) both the cathode and anode are electrochemical Prior to the initial charge or discharge of the cell, the working ions may be substantially absent; d) one of the cathode and anode may comprise metal, may consist essentially of metal, And the other may comprise a semiconductor; e) a catalytic molecule in which one or both of the cathode and anode determine its effective chemical potential Others may include particles relay; f) actuating ions, lithium ion ^(Li +), sodium ion ^(Na +), potassium ion ^(K +), magnesium ions ^{(Mg 2+),} aluminum ^{(Al 3+),} or Any combination thereof may be included; g) the bipolar molecule may be represented by the general formula A _{y Xz} or the general formula A _y-1 X _z ^-q , where A is Li, Na, K, Mg, and / or Al, X is S and / or O, 0 <z ≦ 3, y is a charge neutral of a bipolar molecule of the general formula A _y X _z or of the general formula A _y-1 X _z ^-q H) sufficient to ensure the charge of the -q of the bipolar molecule, and 1 ≦ q ≦ 3); h) up to 50% by weight of the dipole additive I) Dipolar molecular additives are generally During A _y X _z or the formula _{A y-1} ^{X z -q} (wherein, A is Li, Na, K, Mg, and / or Al, X is an S, O, Si, and / or OH , 0 <z ≦ 3, and y secures the charge neutrality of the bipolar molecular additive of the general formula A _y X _z or the charge of ^−q of the bipolar molecular additive of the general formula A _y-1 X _z ^-q A compound or a combination of compounds having a), and an electrochemical cell may have a cycle life of at least 1000 cycles; k) When a cell closes its open circuit, it may exhibit a discharge current even though it has not received energy from an external source; l) the electrochemical cell is subject to certain controls imposed by an external potentiostat In current, charge or discharge current and Or may exhibit a self-cycling component of voltage; m) the electrochemical cell may reversibly and ionize working ions on the anode during charging; n) electrochemical cell May exhibit self-charging without a controlled charging current; o) the electrochemical cell may exhibit a self-charging current component with a controlled charging current component; p) the electrochemical cell Q) the electrochemical cell may exhibit self-charge without a controlled discharge current; r) the electrochemical cell may have 100 May have a charge / discharge coulombic efficiency greater than%; s) the electrochemical cell may exhibit a measured charge or discharge current that is less than the control current; t) the electrochemical cell upon charging Has charging current exceeding control current U) the electrochemical cell may have a measured current in the opposite direction of the control current; v) the electrochemical cell has a measured discharge current greater than the control current upon discharge. And may exhibit both measured discharge current and voltage self-cycling; w) the electrochemical cell may exhibit an alternating current having a period of at least 1 minute; x) the electrochemical cell at least An alternating current having a period of one day may be presented.

  The present disclosure further includes a battery comprising one electrochemical cell as described above, or at least two such cells, which may be in series or in parallel.

  The electrochemical cells and batteries disclosed above and elsewhere herein may be rechargeable.

  For a more complete understanding of the present invention and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings.

FIG. 1A is a schematic cross-sectional view of an electrochemical cell according to the present disclosure prior to initial charging in an open circuit.

FIG. 1B is a schematic cross-sectional view of the electrochemical cell of FIG. 1A during self-charging.

FIG. 1C is a schematic cross-sectional view of the electrochemical cell of FIGS. 1A and 1B during discharge.

FIG. 2 is a schematic diagram of an equivalent circuit that can be used to calculate the time dependence of the evolution of the measured voltage in the open circuit of the electrochemical cell of FIG. 1A.

FIG 3A~3D is a Al-C anode, the S-C-Cu cathode and the test results for an electrochemical cell having a Li + solid glass electrolytes that contain 10% Li ₂ S, is a series of graphs . The measurement voltage is expressed as Vme (t). The measured current is expressed as Ime (t). The control current is represented as Icon (t), and after a short charge (the vertical line on the left side of FIG. 3A) is −1 μA over time (t). FIG. 3A presents the results for an electrochemical cell with self-charging without cycling for 41 hours followed by 27 hours of self-cycling using a cycling period of about 8 minutes. FIG 3A~3D is a Al-C anode, the S-C-Cu cathode and the test results for an electrochemical cell having a Li + solid glass electrolytes that contain 10% Li ₂ S, is a series of graphs . The measurement voltage is expressed as Vme (t). The measured current is expressed as Ime (t). The control current is represented as Icon (t), and after a short charge (the vertical line on the left side of FIG. 3A) is −1 μA over time (t). FIG. 3B presents a graph with an extended time scale for a period between 40 and 42 hours of the graph of FIG. 3A. FIG 3A~3D is a Al-C anode, the S-C-Cu cathode and the test results for an electrochemical cell having a Li + solid glass electrolytes that contain 10% Li ₂ S, is a series of graphs . The measurement voltage is expressed as Vme (t). The measured current is expressed as Ime (t). The control current is represented as Icon (t), and after a short charge (the vertical line on the left side of FIG. 3A) is −1 μA over time (t). FIG. 3C shows that after a second short charge while the electrochemical cell was slowly cooled following a 2 hour heating from 12 ° C. to 22 ° C. starting from 20.5 hours, Results from the second cycle of the 3B electrochemical cell are presented. FIG 3A~3D is a Al-C anode, the S-C-Cu cathode and the test results for an electrochemical cell having a Li + solid glass electrolytes that contain 10% Li ₂ S, is a series of graphs . The measurement voltage is expressed as Vme (t). The measured current is expressed as Ime (t). The control current is represented as Icon (t), and after a short charge (the vertical line on the left side of FIG. 3A) is −1 μA over time (t). FIG. 3D presents a graph that expands the time scale of the period during which the electrochemical cell was heated of the graph of FIG. 3C.

FIG. 4 is a graph of measured discharge voltage versus time after closing the electrochemical cell circuit with Li anode, C-Ni mesh cathode, and Li + solid glass electrolyte. The cycling period for self-cycling is 24 hours.

FIG. 5A is a graph of test results for an electrochemical cell having an Al—C anode, an S—C—Cu cathode, and a Li ⁺ solid glass electrolyte containing 10% Li ₂ S. The measured voltage is expressed as V _me (t). The measured current is expressed as I _me (t). The control current is expressed as I _con (t) and is 0.2 mA during charging and −1 μA during self-charging. FIG. 5B presents an extension of the current axis for a portion of the graph of FIG. 5A.

FIG. 6 is a graph of measured first discharge current versus time after closing the circuit of a jellyroll electrochemical cell with an Al—C anode, a Cu cathode, and a Li + solid glass electrolyte. The discharge was accompanied by a low load resistance.

FIG. 7 is a graph of measured voltage versus time over a 5 hour charge / 5 hour discharge cycle for an electrochemical cell with a Li anode, a γMnO ₂ —C—Li glass-Cu cathode, and a Li + solid glass electrolyte. The electrochemical cell was cycled for 190 days. The peak voltage is indicated by an arrow.

DETAILED DESCRIPTION The present disclosure includes electric dipoles and working ions, and is capable of reversibly plating working ions on either electrode without being resupplied by the other electrode. To an electrochemical cell comprising a solid glass electrolyte, whereby the electrochemical cell exhibits self-charging and self-cycling behavior. The cell typically contains not only mobile alkali metal-operated cations that can be plated without dendrite on a metal current collector, but also more slowly moving molecular electric dipoles. Having a solid electrolyte. The difference in the electrochemical potential of the two electrodes is the driving force that creates an electric double layer capacitor at each electrode / electrolyte interface in an open circuit, as in a normal electrochemical cell. However, the difference between the translational mobility of the working cation and the orientation and translational mobility of the electric dipole causes a slower formation of any excess charge in the electrolyte at the interface. The contribution of bipolar molecules to the interfacial charge can be large enough to induce plating of working cations as an alkali metal layer on the anode, which represents self-charging. If the counter electrode is unable to resupply the last working cation remaining in the electrolyte via this self-plating or at the applied charging power, the electrolyte will reach an equilibrium between plating and stripping It will be negatively charged. The charge in the electrolyte is represented in the equivalent circuit as an inductor in parallel with the capacitor, which creates a self-cycling component of charge or discharge current and / or voltage at a constant control current imposed by an external potentiostat. Can be.

The electrolyte is called glass because it is amorphous so that it can be confirmed through X-ray diffraction. The working ion may be an alkali metal cation such as Li ⁺ , Na ⁺ , K ⁺ , or a metal cation such as Mg ²⁺ and / or Al ³⁺ .

  Self-charging, as described further herein, receives a charging current from an external source, even though the electrochemical cell includes an electrode that does not contain the cell's working ions at the time of fabrication. This refers to the phenomenon of delivering a discharge current when the external circuit is closed. This phenomenon is the result of alignment and transposition of the electric dipoles in the electrolyte after assembly of the cell as a result of the interaction between the dipoles and the internal electric field. The internal electric field produced by the alignment of the dipoles is large enough to plate working ions from the electrolyte as metal on one of the electrodes without resupplying the electrolyte from the other electrode. , Thereby negatively charging the electrolyte. When the external circuit is closed, the working ions return to the electrolyte and electrons are sent to the external circuit where they provide a discharge current.

  Self-cycling occurs when electrolyte working ions are plated on the electrode, which causes the electrolyte to become negatively charged. If the negative charge in the electrolyte is large enough, it strips the plated metal back to the electrolyte as a cation, releasing electrons into the external circuit. The different response speeds of bipolar molecules and ions and electrons in the electrolyte to the external circuit result in cycling of current and / or cell voltage in the external circuit.

  Both self-charging behavior and self-cycling behavior can occur without external energy input, but both phenomena may occur as a component of cell charge / discharge performance with external charge / discharge input. For example, a self-charging electrochemical cell may be provided with a charging current as an external energy input, in which case the cell has a charge greater than that defined by the charging current that gives a Coulomb efficiency greater than 100%. Will be presented. As another example, the discharge current and / or voltage may have a self-cycling component with a frequency different from the charge / discharge cycling frequency.

The solid glass electrolytes of the present disclosure are non-flammable and can be alkali metal plated without dendrite on the electrode current collector and / or on itself. The plated metal atoms are derived from the working ions of the electrolyte. The plated working ions may or may not be resupplied from the other electrode to the electrolyte. Specifically, the solid electrolyte of the present disclosure includes, as working ions, alkali metal cations such as Li ⁺ , Na ⁺ and K ⁺ , metal cations such as Mg ²⁺ and Al ³⁺ , and A ₂ X or AX ⁻ , or Even a glass containing an electric dipole such as MgX or Al ₂ X ₃ , where A = Li, Na or K, and X═O or S or another element or dipolar molecule Good. Suitable A ⁺ glass electrolytes and methods for making them have already been described in WO2015128834 (A Solid Electrolyte Glass for Lithium or Sodium Ion Conduction) and WO2016205064 (Water-Solvated Glass / Amorphous Solid Ionic Conductors). The disclosures for both alkali metal ions are incorporated herein by reference.

In general, the metal working ions in the solid glass electrolyte used in the electrochemical cells of the present disclosure may be alkali metal ions such as Li ⁺ , Na ⁺ , K ⁺ , or Mg ²⁺ or Al ³⁺ , also some of the mobile operating ion binds to the anion, mobility is lower electric dipole (e.g., a 2 _X, AX ^- etc.), or they become larger ferroelectric molecule A condensate may be formed (where A = Li, Na, K, Mg, Al and x = O, S, or another anion atom). The glass may also contain up to 50% by weight of electric dipolar molecules other than those formed from precursors used in glass synthesis without bipolar molecular additives as additives. The presence of the electric dipole increases the dielectric constant of the glass. The dipole is also active in promoting self-charging and self-cycling phenomena. In addition, solid glass electrolytes are not reduced upon contact with metallic lithium, sodium, or potassium, they are spinel Li [Ni _0.5 Mn _1.5 ] O ₄ or olivine LiCo (PO ₄ ) And on contact with high voltage cathodes such as LiNi (PO ₄ ). Thus, no passivated solid electrolyte intermediate phase (SEI) is formed. Further, the surface of the solid glass electrolyte is wetted with an alkali metal, which makes it possible to plate the alkali metal without including dendrites from the glass electrolyte, and the alkali metal is at least 1000 times and at least 2000 times. Or provide a low resistance to ion transfer across the electrode / electrolyte interface over at least 5000 charge / discharge cycles.

  The solid glass electrolyte may be applied as a slurry over a large surface area. The slurry may also be incorporated into paper, or other flexible cellulose or polymer membrane, and when dried, the slurry forms a glass. The membrane structure may have an attached electric dipole or, when in contact with glass, forms an electric dipole that has only rotational mobility. Electric dipoles in glass can have not only translational mobility but also rotational mobility at 25 ° C. The reaction between the dipoles having translational mobility may be accompanied by some dipolar molecular condensation into ferroelectric molecules, forming a region rich in dipolar molecules in the glass electrolyte. The dipole coalescence is called electrolyte aging, which may take several days at 25 ° C, but can be accomplished in minutes at 100 ° C.

  One or more of the dipoles may have some mobility even at 25 ° C. The electrode is made of a current collector and / or a material having an active redox reaction. The electrode current collector is a good metal such as Al or Cu. The current collector may also be in the form of carbon, an alloy, or a compound such as TiN or a transition metal oxide. The current collector may be an electrode without an active material thereon, and the current collector may transport electrons to / from the active material thereon. The active material may be an alkali metal, an alkali metal alloy, or a compound containing atoms of working ions of an electrolyte. The current collector transports electrons to or from the external circuit and to the electrode's own active material, by having electronic contact with the current collector and ionic contact with the electrolyte, Reacts with electrolyte working ions. The ionic contact with the electrolyte may be accompanied only by excessive or insufficient working ion concentration at the electrode / electrolyte interface (this creates an electric double layer capacitor (EDLC)) and it is at the electrode surface It may be accompanied by chemical phase formation. In rechargeable cells, any chemical formation on the electrode surface and EDLC beyond the electrode / electrolyte interface is reversible.

  In accordance with the present invention, one or both electrodes in an electrochemical cell do not contain any detectable atoms of electrolyte working ions, up to 7000 ppm, for example by atomic absorption spectroscopy, during fabrication. It is just a current collector. However, after assembly of the cell, the atoms of the electrolyte working ions can be detected on the electrode by atomic absorption spectroscopy or other means.

  In addition, one or both electrodes of the cell may contain additional electrons, such as carbon, that assist in plating working cations on the current collector without significantly changing the effective Fermi level of the composite current collector. A conductive substance may be contained.

Solid glass electrolyte, dielectric constant greater, for example may have 10 ² or higher relative dielectric constant and (σ _R). The solid glass electrolyte is non-flammable and may have an ionic conductivity σ _A for working ions A ⁺ of at least 10 ⁻² S / cm at 25 ° C. This conductivity is comparable to the ionic conductivity of conventional flammable organic liquid electrolytes used in Li-ion batteries, thereby making the cell safe.

Solid glass electrolytes contain crystalline electronic insulators containing working ions or constituent precursors thereof (typically containing working ions bound to O, OH, and / or halides). It can be formed by conversion to a conductive glass / amorphous solid. This process can be performed similarly in the presence of bipolar molecular additives. A crystalline electronic insulator containing working ions or a constituent precursor thereof has the general formula A _3-x H _x OX (where 0 ≦ x ≦ 1 and A is at least one alkali metal; X may be a substance having at least one halide. Water may exit from the solid glass electrolyte during formation.

An electrochemical cell containing a solid glass electrolyte as disclosed herein may have a large energy gap E _g , where E _g = E _e −E _v . E _c is the bottom of the conduction band, E _c > μ _A , where μ _A is the anode chemical potential. E _v is the top of the valence band, E _v <μ _C , where μ _C is the cathode chemical potential. The energy difference μ _A −μ _C may promote self-charging and self-cycling behavior. In addition, due to the dipole contribution, the electrochemical cell has an electrolyte other than the solid glass electrolyte as disclosed herein, otherwise higher than the capacitance in the same electrochemical cell. , Having capacitance in open circuit or closed circuit.

  Electrochemical cells containing solid glass electrolytes as disclosed herein may also be capable of plating working ions and stripping from one or both electrodes, so that the electrolyte and / or at least one is The electrolyte-electrode coupling between the two electrodes is sufficiently strong for electrolyte volume changes during cycling that are substantially perpendicular to the interface between the electrolyte and the electrode. Typically, this bond is strong enough between the electrolyte and both electrodes for electrolyte volume changes that are substantially perpendicular to both interfaces between the electrolyte and both electrodes. is there.

In the following, the control current I _con is the current specified by the potential difference between the two electrodes controlled by the load in the potentiostat, while the measured current I _mc is the current specified by the potentiostat and the self Actual measured current, including current resulting from charging. The current generated as a result of self-charging may be in the same direction as I _con during discharge or in the opposite direction. In order to specify whether the present inventors indicate discharge current and voltage or charging current and voltage, subscripts “dis” and “ch” are attached.

An electrochemical cell as disclosed herein may have a measured discharge current I _me-dis and / or a measured charge current I _me-ch that is less than the control current I _con .

During charging, an electrochemical cell as disclosed herein may have a charging current I _ch that exceeds the control current I _con . During discharge, an electrochemical cell as disclosed herein may have a measured discharge current I _me-dis that is greater than the discharge control current I _dis-con . Such electrochemical cells may exhibit self-cycling of both measured discharge current I _me-dis and voltage V _me-dis in addition to normal discharge.

  An electrochemical cell as disclosed herein may generate a voltage in open circuit equal to or lower than the theoretical voltage as a result of differences in the electrochemical potential of the electrodes.

  An electrochemical cell as disclosed herein may have a self-voltage that is large enough to cause working ions in the electrolyte to be plated on the anode in an open circuit. Furthermore, the power delivered by this self-charging may be sufficient to light the red LED for over a year.

An electrochemical cell as disclosed herein may exhibit ion plating on either electrode current collector when subjected to a constant I _con or V _con . Plating of working cations from the electrolyte without being resupplied by the counter electrode can result in a self-cycling component of the measured current I _me and measured voltage V _me .

In the following, the control current I _cm is the current specified by the potential difference between the two electrodes controlled by the load in the potentiostat, while the measured current I _me is the current specified by the potentiostat and the self Actual measured current, including current resulting from charging. The current generated as a result of self-charging may be in the same direction as I _con during discharge or in the opposite direction. In order to specify whether the present inventors indicate discharge current and voltage or charging current and voltage, subscripts “dis” and “ch” are attached.

  An electrochemical cell as disclosed herein may exhibit self-cycling during a given cycle period. Due to self-charging, the period of self-cycling is independent of the charge / discharge period.

The measured current I _me of an electrochemical cell as described herein includes both a direct current component and an alternating current component. In some applications, only the AC portion can be used, for example, in signal transmission. The AC period is a self-cycling period that can have a period between minutes and days.

  The principles by which an electrochemical cell as disclosed herein may operate will be better understood by referring to FIG. 1, which illustrates FIG. 1A illustrating an electrochemical cell 100 prior to cycling. 1B illustrating the electrochemical cell 100 during self-charging and FIG. 1C illustrating the electrochemical cell 100 during discharging.

  In FIGS. 1A, 1B, and 1C, the electrochemical cell 100 includes an anode 10 having a contact 15, a cathode 20 having a contact 25, and a solid alkali metal ion glass electrolyte 30. Excess working ions in the electrolyte 30 are represented by + circles. The depletion of working ions in the electrolyte 30 is represented by -circles. Electric dipoles in the electrolyte 30 are represented by +/− ellipses. The electronic charge in the electrode is represented by + and − circles. In FIGS. 1B and 1C, the circled arrows represent the direction of charge movement associated with excess mobile cations or lack of mobile cations in the electrolyte, electrons in the electrode.

FIG. 1A schematically illustrates an electrochemical cell 100 in an open circuit. The chemical potential (μ _A ) of the anode 10 is higher than the chemical potential (μ _C ) of the cathode 20. In order to balance the energy between the anode chemical potential and the cathode chemical potential, electric double layer capacitors 40a and 40b are formed at the interface between the electrode and the electrolyte. The energy for forming these electric double layer capacitors 40a and 40b is supplied by the difference in the chemical potential of anode 10 and cathode 20.

One such electrochemical cell 100 may have an alkali metal anode 10 and a Cu cathode 20 with alkali metal working ions (A ⁺ ) in the solid glass electrolyte 30.

The transposition of working ions (A ⁺ ) and electric dipoles in the solid glass electrolyte 30 allows the formation of electric double layer capacitors 40a and 40b. As illustrated in FIG. 1A, in an open circuit, the electric double layer capacitor 40 a at the interface of the anode 10 (which is the negative terminal of the electrochemical cell 100) and the electrolyte 30 causes excess working ions in the electrolyte 30. (Represented as +) due to the movement of the working ions in the electrolyte 30 towards its anode side. The portion at the interface of the anode 10 will have an excessive negative electronic charge (denoted as-) and on the electrolyte side of the interface between the anode (1) and the electrolyte 30 separated from each other, With an excess of positive cationic charge that is compensatory.

  The electric double layer capacitor 40b at the interface of the cathode 20 (which is the positive terminal of the electrochemical cell 100) and the electrolyte 30 has a depletion of working cations in the electrolyte 30 (represented as −), This is due to the movement of working ions in the electrolyte 30 toward the anode side and away from the cathode side. The portion at the cathode 20 interface has an excess of positive electronic charge (denoted as +) that is compensatory at the cathode 20 away from the interface with the electrolyte 30.

  The electrolyte 30 has a neutral net charge except at the interface with the electrodes having different charges as described above.

  The movement of working ions in the electrolyte 30 and the resulting formation of the electric double layer capacitors 40a and 40b occurs fairly quickly once the electrochemical cell 100 is assembled.

  Due to the movement of the working ions in the electrolyte 30 and the resulting electric field in a direction that balances the difference in the electrochemical potential of the two electrodes, the electric dipole in the solid glass electrolyte becomes + and in FIG. As illustrated by the-sign, they themselves face their negative ends towards the interface between the electrolyte 30 and the anode 10 and their positive ends towards the interface between the electrolyte 30 and the cathode 20. It tends to be oriented.

The alignment of the electric dipoles and their translational movements are not instantaneous and are a much slower process than the formation of the electric double layer capacitors 40a and 40b. As a result, the open circuit voltage (Voc (t)) measured over time progresses as alignment and dipole translation occur. This evolution of Voc (t) can be modeled by using an equivalent circuit as shown in the schematic diagram of FIG. The schematic of FIG. 1A represents a hypothetical electrochemical cell 100 in which all the dipoles a in the solid glass electrolyte 30 are aligned and transposed. In practice, complete alignment and transposition is unlikely to be achieved, and dipole translation and alignment increase as Voc (t) progresses. Increasing dipole alignment also enhances the electric field across electrolyte 30 and facilitates further dipole alignment and movement. Maximum alignment and movement in a given electrochemical cell 100 is at least 1 minute for alignment when V _oc ceases to change in a consistent direction over time or, for example, depending on temperature or It can be inferred that it occurred during a given period, such as at least 5 minutes and several days or minutes for the transfer.

  In some cases, the additional electric field created by the alignment and movement of the dipoles in the electrolyte 30 even promotes plating of working ions on the anode 10 when the electrochemical cell 100 is open circuit. May be sufficient. Eventually, the net negative charge that electrolyte 30 generates as a result of this plating process will be high enough that it cannot be overcome by an electric field, and plating on anode 10 will end.

FIG. 1B illustrates the electrochemical cell 100 when the circuit of the electrochemical cell is first closed, for example by connecting external circuitry to the contacts 15 and 25. The external circuit includes a potentiostat that imposes a charge control current I _con that may be less than some critical current I _c . The critical current is the maximum I _con-dis when the self-charging phenomenon still exists as shown in FIG. 1B. When the circuit is closed, the energy stored in the electric double layer capacitors 40a and 40b and by the aligned dipoles in the electrolyte 30 leads to the charging current _Ich . This phenomenon causes the electrochemical cell 100 to self-charge.

During self-charging, while the discharge control current I _con is applied, some electrons are transported from the cathode 20 to the anode 10 where they are near the interface with the reduced anode 10. Excess working ions therein are reduced and then plated onto anode 10 to form plated metal 50.

  Cathode 20 is devoid of working ions and, therefore, depletes working ions from electrolyte 30 to form plated metal 50 so that cathode 20 cannot resupply working ions. Thus, the electrolyte 30 at the interface with the anode 10 becomes more and more negatively charged, and eventually the working ions are no longer plated on the anode 10 as the plated metal 50 and the working ions are stripped into the electrolyte. Reach the starting point.

Alternatively, because the plated metal is very thick, the electrode chemical potential is not the chemical potential of the current collector 10 but the plated metal chemical potential, thereby plating the working cation as metal 50 from the electrolyte. It may be more difficult to do so and may terminate the plating process. In either case, the measured charging current I _me-ch decreases as the working ion plating on the anode 10 decreases.

In addition, the initial electrons that are removed from the cathode by the charging current I _ch, holds the electric double layer capacitor 40b, as a result, moving the dipoles in the direction 70 towards the cathode 20. However, the working ions in the electrolyte 30 do not move toward the cathode 20.

Finally, depletion of working ions from the electrolyte 30 near the anode 10 induces its delamination back from the plated metal 50 back to the electrolyte 30 in the discharge phase, further reducing I _{me-ch and} Double layer capacitors 40a and 40b are restored (not shown). Finally, since the energy stored in the electric double layer capacitor is sufficiently high, further delamination of working ions from the plated metal 50 can still contribute to generating sufficient additional energy. Otherwise, plating of working ions onto the anode 10 as plated metal 50 begins again, increasing I _me-ch .

  Although the above description has been presented in a simplified manner where plating and stripping always occur, in an actual electrochemical cell 100, plating and stripping typically occurs during at least a portion of each cycle. Both occur at the same time, but one process is dominant, so that there is final plating or final stripping.

  This change between the final plating and final stripping of the working ions, derived from the plated metal 50 on the anode 10, of the electrochemical cell 100 with simultaneous cycling of voltage (V). Bring self cycling. This self-cycling occurs in a given cycle period, which tends to remain constant as long as cycling continues. The cycle duration depends on the difference in electron velocity versus the translational velocity of the cation and dipole.

In an electrochemical cell 100, such as the electrochemical cell of FIG. 1B, where I _con is less than I _c , the cycle period can be approximately a few minutes between 1 minute and 10 minutes.

FIG. 1C shows the electricity during discharge through an external circuit including a potentiostat that imposes a control current I _con that exceeds the critical current I _c , as in a low load external circuit, which may include a light emitting diode (LED). A chemical cell 100 is illustrated. As with the electrochemical cell of FIG. 1B, once the circuit is closed, energy is stored in the electric double layer capacitors 40a and 40b and by the aligned dipoles in the electrolyte 30.

During discharge, the current I _dis is produced by I _con and can be controlled thereby. The load on the external circuit is low enough that electrons flow from the anode 10 to the cathode 20 and attract working ions from the electrolyte 30 to the cathode 20, where they combine with the electrons and are plated onto the cathode 20. The formed metal 60 is formed. The transfer of electrons from the anode 10 to the cathode 20 reduces both the electric double layer capacitors 40a and 40b, but it reduces the electric double layer capacitor 40b primarily at the electrolyte-cathode interface. This reduces the electric field across the electrolyte 30 and allows working ions to be plated on the cathode 20. Although the electric double layer capacitor 40b is depleted, typically, as long as most of the dipoles in the electrolyte 30 remain oriented as if the electrochemical cell 100 was open circuit, It will not be destroyed. However, the dipole in the electrolyte 30 is compressed in the direction 80.

Since anode 10 is substantially devoid of working ions and therefore depletes working ions from electrolyte 30 to form plated metal 60, anode 10 cannot resupply working ions. In addition, changes in the internal electric field of the electrolyte 30 created by electron transfer that occurs much faster than working ions and electric dipoles can redistribute them and accommodate them in alignment. Thus, the electrolyte 30 at the interface with the cathode 20 will become increasingly negatively charged, eventually reaching a point where the working ions will also be stripped from the plated metal 60 and back to the electrolyte 30; The result is a measured discharge current I _me , which is increasingly lower until it reaches the minimum value of I _me before the plating and stripping are in equilibrium.

  Alternatively, in some electrochemical cells 100, the plated metal 60 may eventually become very thick, effectively blocking the electrolyte 30 from the cathode 20 and substantially reducing the working ions in the electrolyte 30. All, compared to the anode 10, sufficient chemical potential to cause additional plating based solely on the difference in chemical potential or based on the difference in chemical potential combined with any remaining electric field in the electrolyte 30. Exposed to plated metal 60 that has no difference in. In such cases, working ions can no longer be plated onto the cathode 20 as the plated metal 60.

I _me increases as the working ions become plated metal 60. When I _me reaches a maximum, the process is reversed and the working ions are again plated onto the cathode 20 as a metal plate 60.

This change between working ion plating and stripping from the plated metal 60 on the cathode 20 results in self-cycling of the electrochemical cell 100 with simultaneous cycling of voltage and I _me . This self-cycling occurs in a given cycle period, which tends to remain constant as long as cycling continues. The cycle period depends on the rate of compression of the dipole in the electrolyte 30 in the direction 80 during discharge and their expansion during charging. Typically, an increase in I _me toward the maximum is faster than a decrease in it toward the minimum.

In an electrochemical cell 100, such as the electrochemical cell of FIG. 1C, where I _con exceeds I _c , the duration can be approximately several days, such as 1 day and 7 days.

Electrons can only pass through the LED in one direction. Thus, in actual use of the electrochemical cell 100, the anode 10 becomes increasingly positive until the electric field across the electrolyte 30 reverses the orientation of the electric dipole and then switches off the current flowing through the load. Charged, the cathode 20 becomes increasingly negatively charged. For electrochemical cells with low I _{me, the} time required for this to occur can be very long, even over a year. Thus, the electrical device can be powered by the electrochemical cell 100 for that length of time without the input of external energy.

In the electrochemical cell 100 both electrodes before the assembly of the cell lacks actuating ions substantially external charging current I _ch is, it may produce a large electric double layer capacitor 40a and 40b, thereby, Working ions can be plated from the electrolyte 30 onto the anode 10. This is because such plating occurs during charging of conventional rechargeable electrochemical cells. However, depletion of working ions from the electrolyte 30 without resupply from the cathode 20, in contrast to conventional rechargeable electrochemical cells where such resupply occurs, electrolyte near the anode 10. As the negative charge in 30 increases, it causes an increase in resistance to further plating on the anode 10. In addition, changes in the electric field across the electrolyte 30 due to the inclusion of molecules and atoms in the electrolyte, which is slower than the movement of electrons in the current collector, changes the rate of self-charging and self-cycling. Thus, as with the electrochemical cell of FIG. 1B above, delamination of working ions from the anode 10 also occurs. Eventually, an equilibrium between working ion plating and stripping at the anode 10 is reached at a certain controlled external charging current I _con-ch .

In such an electrochemical cell, the measured charging current I _me-ch is larger than the constant control external charging current I _con-ch . This is because the electric double layer capacitors 40a and 40b are charged in addition to the working ions being plated and stripped. In addition, the magnitudes of the measured charging voltage V _me-ch and the measured charging current I _me-ch change periodically with time due to alternating plating and peeling.

In such a cell, the average of I _me-ch may be equal to or greater than I _con-ch while working ions are stripped from the anode 10 and plated onto the anode 10. When plating / and peeling at the anode 10 continues, the electric double layer capacitor 40a near the anode 10 is also charged. Eventually, the electric double layer capacitor 40a is charged enough that the negative charge on the anode side blocks electrons from returning to the anode 10, thereby preventing further detachment of the working ions from the anode 10. To do. In this respect, continuous charging can charge only the electric double layer capacitor 40a. As a result, voltage self-cycling stops and the voltage increases linearly with time at a rate that depends on I _con-ch .

In one variation, if the working ions were plated on the cathode 20 before the external charging current was applied, the measured discharge current I _me-dis is determined until the working ions are substantially stripped from the cathode 20. Repeat self cycle. However, the measured discharge voltage V _me does not repeat the cycle.

In FIG. 2, inductance is introduced into the equivalent circuit to represent the role of negative charges introduced into the electrolyte 30 by plating of working cations from the electrolyte without resupplying the electrolyte from the counter cation. . In FIG. 2, C represents the capacitance of the series set of 40a and 40b EDLCs, _RL represents the plating resistance,
Represents a driving force.

  The electrochemical cells of the present disclosure can be used in batteries. Such a battery may be a simple battery that includes few components other than electrochemical cells, and a casing or other features. Such batteries may be standard battery formats such as coin cell, standard jelly roll, pouch, or prismatic cell formats. They may also be in a more adapted format, such as a fitted prismatic cell.

  The electrochemical cells of the present disclosure can also be used in more complex batteries, such as batteries containing complex circuits, and in processor and memory computer-implemented monitoring and regulation.

  Regardless of simplicity, complexity, or format, all batteries that use the electrochemical cells of the present disclosure have improved safety, especially when damaged when compared to batteries with organic liquid electrolytes. It may present a lower tendency to catch fire.

  A battery may include a single electrochemical cell as disclosed herein, and two or more such cells (these may be connected in series). , May be connected in parallel).

  Electrochemical cells as disclosed herein and batteries containing them may be rechargeable.

  The electrochemical cells of the present disclosure can also be used in devices that utilize electric double layer capacitors, such as capacitors. The electrochemical cells of the present disclosure can also be used in devices that utilize cycle periods, particularly AC periods, such as signaling devices.

  By way of example, the electrochemical cell of the present disclosure can be used as a ferroelectric gate of a field effect transistor; in a portable handheld and / or wearable electronic device, such as a phone, watch, or laptop computer; In devices such as desktop or mainframe computers; in power tools such as power drills; electric or hybrid aircraft, land vehicles or water vehicles such as boats, submarines, buses, trains, trucks, cars, motorcycles, engines In bicycles, powered bicycles, airplanes, drones, other flying vehicles, and their toy versions; for other toys; for energy storage, eg derived from wind, sun, hydropower, waves, or nuclear energy In the storage of electricity And / or for small-scale use, such as for homes, businesses, or hospitals, in grid storage or as stationary power storage; for sensors, eg portable medical or environmental sensors; For example, for underwater communication; as a capacitor in a supercapacitor or coaxial cable; or as a transducer.

  The following examples are provided to further illustrate the principles and specific embodiments of the present invention. They are not intended to be exhaustive of the full scope of all embodiments of the invention and should not be construed as such.

Example 1
I _con <I _c in electrochemical cell

FIG. 3 shows an electrochemical cell (Al—C / Li + glass / S—C— with an Al—C anode, an S—C—Cu cathode, and a Li ⁺ solid glass electrolyte containing 10 wt% Li ₂ S. The results of experiments demonstrating self-charging and self-cycling of Cu cells) are presented.

  The Al anode had a carbon layer (Al-C) in contact with the Li glass electrolyte. The cathode was a Cu current collector with a carbon layer containing a sulfur relay in contact with the Li glass electrolyte.

In FIG. 3A, the measured voltage versus time of the electrochemical cell showed a 0.5 mA charge for 25 minutes after 6 hours and 26 minutes, followed by a rapid discharge of the electric double layer capacitor. The voltage at a constant I _con hardly increased during the next 8 hours 22 minutes because the electric double layer capacitor had been recharged, and then with a small amplitude noise over the next 35 hours 29 minutes. Increased to 4V. The measured voltage V _{me of} 2.4 V was the maximum voltage for self-charging plating of lithium metal Li ⁰ onto the anode. A brief pause at the rate of voltage increase occurred before the oscillation began when V _me was 2.2V. The theoretical V _me for (μ _A −μ _C ) / e was 2.2V. Once the plated Li ⁰ thickness on the Al—C anode reaches a critical thickness, Li ⁰ plating / peeling is performed by plating in μ _A (Li) -μ _C (Cu) and μ _A (Al Oscillated between plating in) -μ _C (Cu).

FIG. 3B shows the onset of self-cycling between [μ _A (Li) −μ _C (Cu)] / e and [μ _A (Al) −μ _C (Cu)] / e in the measurement of FIG. 3A. The image is shown and the vibration can be seen more clearly.

FIG. 3C shows the V _me of the cell of FIG. 3A in a second cycle at constant I _con after the initial charge of Co ₂ mA for 25 minutes. During self-charging, after charging the electric double layer capacitor, Li ⁺ from the glass electrolyte was plated on the Al anode, and Li ⁺ working ions were not re-supplied from the Cu cathode to the electrolyte. When V _me reached 1.65 V, self-cycling began with an average of V _me of approximately 1.7 V, as further seen in the enlarged FIG. 3D.

When the temperature of the electrochemical cell was increased by heating from 12 ° C. to 26 ° C., a sharp drop in V _me occurred. The electrochemical cell was then removed from the heater and left to slowly return to 12 °. During cooling, V _me rose to 2.1 V, which is the difference between the chemical potential of Al and Cu. At this voltage, the electrochemical cell began to plate working ions again, but with no periodic cycling until a small discharge occurred, followed by a longer period of cycling. Discharge of the electric double layer capacitor occurred to V _{me of} approximately 1.4V. At that point, plating began again. Throughout these voltage changes, the measured charging current I _me remained almost constant with only a small decrease during the last plating that was abruptly terminated during the last discharge recorded. Changes with temperature reflect the movement of ions and molecules in the electrolyte.

(Example 2)
I _con > I _c in the external circuit including the LED

Build an electrochemical cell (Al / Li ⁺ glass / Cu cell) with an Al anode, Cu cathode, and an electrochemical cell with Li + solid glass electrolyte, then connect in series to light up the red LED in the external circuit did. These cells exhibited self-charging with a discharge current I _dis exceeding the critical current I _c . The electrochemical cell was cycled in advance but was not charged, otherwise it was not supplied by external energy input. The cell supplied power to the LED for approximately two years. The data per cell for the first year is presented in Table 1. The total density of energy delivered in the first year was 373.8 Wh / g.

Example 3
I _con > I _c in an electrochemical cell having a Li anode

FIG. 4 shows the measurement of a discharge electrochemical cell (Li metal / Li + glass / C-Ni cell) with a Li metal anode, Li ⁺ glass electrolyte, and a C—Ni cathode (carbon is placed in a Ni mesh). The voltage V _me (t) is presented. The load resistance was 1 megohm and the discharge current was approximately 2.5 μA. Periodic hills in voltage were the result of periodic self-cycling of self-charging components in cell discharge compounds. The plating on the cathode had a longer duration than the plating on the anode (as shown in FIG. 3B). Due to the excess energy delivered by self-charging, the electrochemical cell exhibited a charge / discharge coulombic efficiency of over 100% during cycling.

Example 4
Constant applied charging current (I _con-ch )> I _c

FIG. 5A shows a measured charge with a constant charge control current I _{con-ch in} an Al—C / Li ⁺ glass / S—C—Cu cell such as the cell used in Example 1 in the second charge / discharge cycle. Data showing self-cycling of current I _me-ch is presented. After the first discharge, the cell was recharged with an external power source. The measurement voltage (V _me ) was 2.1 V, corresponding to [μ _A (Al) −μ _C (Cu)] / e. More than _{I con} I _me-ch, as seen in FIG. _{5B, I me-ch} is to remain above the _{I con,} exhibited self cycling having a certain amplitude.

I _me-ch remains above I _con-ch , because the lithium metal delamination from the cathode contributes to I _me-ch and the electrolyte charge localized near the electrolyte and cathode interface. It was shown to be accompanied by plating / peeling cycling, which must be due to This is because any possible resupply of Li ⁺ from the anode takes longer than a short self-cycling period. The average of I _me-ch remained constant until most of the lithium metal, if not all, was stripped from the cathode and the cathode electric double layer capacitor began charging. Since the cycling phenomenon was localized at the cathode / electrolyte interface, there was no corresponding cycling of V _me .

(Example 5)
I _dis > I _{c in a jellyroll} electrochemical cell

FIG. 6 presents the measured discharge current I _me of a jellyroll Al—C / Li ⁺ glass / Cu cell with a low load resistance R _L of 0.1Ω but otherwise similar to that of Example 2. doing. In the open circuit, the cathode electric double layer capacitor was depleted of Li ⁺ in the electrolyte at the interface of the electrolyte with the cathode. When the circuit was closed, electrons from the anode imparted a negative charge to the Cu cathode, which pulled Li ⁺ back to the cathode interface. However, ion movement was slower than electron movement, and thus I _me increased with the rate of movement of Li ^{+ back} to the cathode / electrolyte interface. At the critical voltage of the electrolyte / cathode electric double layer capacitor, Li ⁺ from the electrolyte was plated on the cathode as lithium metal and I _me suddenly dropped. Subsequent reconstruction of the cathode / electrolyte electric double layer capacitor was more time consuming because the negative charge of the electrolyte hindered Li ⁺ migration to the cathode / electrolyte interface where plating occurred again.

(Example 6)
Charge / discharge cycling of all-solid-state lithium electrochemical cells

FIG. 7 shows an electrochemical cell having a MnO ₂ —C—Li—glass—Cu cathode with a γMnO ₂ catalytic relay in a carbon layer in contact with a Li anode, a Li ⁺ glass electrolyte, and a Cu current collector (Li / FIG. 5 shows the charge and discharge voltage variation over time during cycling of Li ⁺ glass / MnO ₂ —C—Cu cells. Each cycle was 10 hours 30 minutes for 444 cycles with a control current I _con of 70 μA and a measured discharge current I _me of 53 μA.

I _me that is less than I _con indicates the presence of a self-charging current that opposes the discharge I _con . The V _me profile showed a typical cycling for self-charging due to plating onto the anode over Li ⁺ re-supplied to the electrolyte by delamination from the cathode. The discharge voltage profile also showed a long cycle period of 34 days.

  The subject matter disclosed above is exemplary and should not be considered limiting, and the appended claims are intended to cover all such modifications as fall within the true spirit and scope of this disclosure. It is intended to cover forms, enhancements, and other embodiments. Accordingly, to the maximum extent permitted by law, the scope of the present disclosure should be determined by the broadest allowable interpretation of the following claims and their equivalents, and is limited or limited by the foregoing detailed description. Should not be done.

Claims (24)

A solid glass electrolyte comprising alkali metal working ions and bipolar molecules conducted by said electrolyte; and
An anode having an active anode chemical potential mu _A,
An electrochemical cell comprising a cathode having an effective cathode chemical potential μ _C ,
One or both of the cathode and anode substantially lacks the working ions prior to initial charge or discharge of the electrochemical cell;
In an open circuit prior to initial charge or discharge, μ _A and μ _C at one or both of the interface between the solid glass electrolyte and the anode and the interface between the solid glass electrolyte and the cathode. An electrochemical cell in which an electric double layer capacitor is formed due to the difference between.   The electrochemical cell according to claim 1, wherein at least one or both of the cathode and the anode comprises a metal.   The electrochemical cell of claim 1, wherein both the cathode and the anode are substantially devoid of the working ions prior to initial charge or discharge of the electrochemical cell.   The electrochemical cell of claim 1, wherein one of the cathode and the anode is a metal and the other comprises a semiconductor.   The electrochemical cell of claim 1, wherein one or both of the cathode and the anode comprises a catalytic molecule or particle relay that determines its effective chemical potential. The working ion is lithium ion (Li ⁺ ), sodium ion (Na ⁺ ), potassium ion (K ⁺ ), magnesium ion (Mg ²⁺ ), aluminum (Al ³⁺ ), or any combination thereof. 2. The electrochemical cell according to 1. The bipolar molecules have the general formula _A y _{X z} or the formula _{A y-1} ^{X z -q,} wherein, A is Li, Na, K, Mg, and / or Al, X is S and And / or O, 0 <z ≦ 3, and y is the charge neutrality of the bipolar molecule of general formula A _y X _z or the charge of ^−q of the bipolar molecule of general formula A _y-1 X _z ^-q. The electrochemical cell according to claim 1, which is sufficient to ensure and 1 ≦ q ≦ 3.   The electrochemical cell according to claim 1, wherein the bipolar molecule comprises up to 50 wt% bipolar molecule additive. The dipoles additive comprises a combination of the general formula _A y _{X z} or the formula _{A y-1} ^{X z -q} one having a compound or compounds, in the formula, A Li, Na, K, Mg, and / Or Al, X is S, O, Si, and / or OH, 0 <z ≦ 3, and y is a charge neutral or general formula of the bipolar molecular additive of the general formula A _y X _z The electrochemical cell according to claim 8, which is sufficient to ensure a charge of −q of the bipolar molecule additive of A _y−1 X _z ^−q and 1 ≦ q ≦ 3.   The electrochemical cell of claim 1, wherein the electrochemical cell has a cycle life of at least 1000 cycles.   The electrochemical cell of claim 1, wherein the electrochemical cell exhibits a discharge current when closing its open circuit without receiving energy from an external source.   The electrochemical cell of claim 1, wherein the electrochemical cell exhibits a self-cycling component of charge or discharge current and / or voltage at a constant control current imposed by an external potentiostat.   The electrochemical cell of claim 1, wherein the electrochemical cell is reversibly plated with the working ions on the anode and without dendrite during charging.   The electrochemical cell of claim 1, wherein the electrochemical cell exhibits self-charge without a controlled charging current.   The electrochemical cell of claim 1, wherein the electrochemical cell exhibits a self-charging current component with a controlled charging current component.   The electrochemical cell of claim 1, wherein the electrochemical cell exhibits a self-charging component without a controlled discharge current.   The electrochemical cell according to claim 1, wherein the electrochemical cell exhibits self-charging without a controlled discharge current.   The electrochemical cell of claim 1, wherein the electrochemical cell has a charge / discharge coulomb efficiency greater than 100%.   The electrochemical cell of claim 1, wherein the cell exhibits a measured charge or discharge current that is less than a control current.   The electrochemical cell according to claim 1, wherein the electrochemical cell has a charging current exceeding a control current during charging.   The electrochemical cell of claim 1, wherein the electrochemical cell has a measured current in a direction opposite to a control current.   The electrochemical cell of claim 1, wherein the electrochemical cell has a measured discharge current that is greater than a control current upon discharge and exhibits self-cycling of both the measured discharge current and the voltage.   The electrochemical cell of claim 1, wherein the electrochemical cell exhibits an alternating current having a period of at least 1 minute.   The electrochemical cell of claim 1, wherein the electrochemical cell exhibits an alternating current having a period of at least one day.