WO2019191054A1

WO2019191054A1 - Electrochemical cell with insulator relay layer

Info

Publication number: WO2019191054A1
Application number: PCT/US2019/024014
Authority: WO
Inventors: John B. Goodenough; Maria Helena Sousa Soares De Oliveira Braga; Andrew Murchison; Joana Cassilda RODRIGUES ESPAIN DE OLIVEIRA
Original assignee: Board Of Regents, The University Of Texas System; Universidade Do Porto
Priority date: 2018-03-27
Filing date: 2019-03-26
Publication date: 2019-10-03

Abstract

The present disclosure provides electrochemical cell. The electrolyte side includes an anode including an anode electrochemically active material including a metal and a solid glass electrolyte adjacent a side of the anode. The solid glass electrolyte includes a cation of the anode electrochemically active material and an electric dipole having the formula A2X or AX^-, or MgX or Al₂X₃. The cathode side includes a cathode including a cathode electrochemically active material and a cathode current collector. The insulator relay layer is adjacent the electrolyte side on one side of the insulator relay layer and adjacent the cathode side on the other side of the insulator relay layer, ionically separates the electrolyte side and the cathode side, and includes a relay. The anode has a Fermi level higher than a Fermi level of the relay and the Fermi level of relay sets a Fermi level of the cathode.

Description

ELECTROCHEMICAL CELL WITH INSULATOR RELAY LAYER

TECHNICAL FIELD

The present disclosure relates to an electrochemical cell containing an anode containing an anode current collector, an anode metal, and a solid glass electrolyte containing cations of the anode metal. The electrochemical cell also contains a cathode containing a cathode current collector and a cathode metal. An insulator relay layer is present between the solid glass electrolyte and the cathode metal and/or between a polymer/plasticizer and the cathode metal. The cathode metal and the anode metal may be different metals or they may be the same metal, so long as they have different electrochemical potentials (Fermi levels) when arranged in the electrochemical cell.

BACKGROUND

An electrochemical cell has two electrodes, the anode and the cathode, separated by an electrolyte. In a traditional electrochemical cell, materials in these electrodes 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 are able to gain and lose ions, typically the same ion, which is referred to as the working ion of the battery. The electrolyte is a conductor of the working ion, but normally it is not able to gain and lose ions. The electrolyte is an electronic insulator, it does not allow the movement of electrons within the battery. In a traditional electrochemical cell, both or at least one of the anode and the cathode contain the working ion prior to cycling of the electrochemical cell.

The electrochemical cell operates via a reaction between the two electrodes that has an electronic and an ionic component. The electrolyte conducts the working ion inside the cell and forces electrons also involved in the reaction to pass through an external circuit.

A battery may be a simple electrochemical cell, or it may be a combination of multiple electrochemical cells. SUMMARY

The present disclosure provides electrochemical cell including and an electrolyte side, a cathode side, and an insulator relay layer. The electrolyte side includes an anode including an anode electrochemically active material including a metal. The electrolyte side also includes a a solid glass electrolyte adjacent a side of the anode. The solid glass electrolyte includes a cation of the metal in the anode electrochemically active material and an electric dipole having the formula A2X or AX , or MgX or AI2X3 wherein A = Li, Na, or K and X = oxygen (O) or sulfur (S) or combinations thereof. The cathode side includes a cathode including a cathode electrochemically active material. The cathode side also includes a cathode current collector adjacent a side of the cathode. The insulator relay layer is adjacent the electrolyte side on one side of the insulator relay layer and adjacent the cathode side on the other side of the insulator relay layer. The insulator relay layer ionically separates the electrolyte side and the cathode side. In addition, the insulator relay layer includes a relay. The anode has a Fermi level higher than a Fermi level of the relay and the Fermi level of relay sets a Fermi level of the cathode.

The above electrochemical cell may also have any of the following additional features, which may be combined with one another in any and all possible combinations unless clearly mutually exclusive:

i) the metal in the anode electrochemically active material may be lithium (Li), sodium (Na), potassium (K), aluminum (Al), magnesium (Mg), combinations thereof, or alloys thereof;

ii) the electrolyte side may include an anode current collector adjacent the anode on a side opposite the solid glass electrolyte;

iii) the anode current collector may include copper (Cu) or stainless steel

(SS);

iv) the solid glass electrolyte may include a dipole additive having a general formula Q_yX_z or Q_y-iX_z ^q, or polarized chains that are combinations of coalescent dipoles represented by both general formulas, wherein Q is Li, Na, K, Mg, or Al, or combination thereof, X is S, O, silicon (Si), or hydroxide (OFF) or a combination thereof , 0<z<3, 0<y<3 and l<q<3; v) the solid glass electrolyte may have a dielectric constant of at least

5000;

vi) the cathode electrochemically active material may include a metal; vii) the metal in the cathode electrochemically active material may include lithium (Li), sodium (Na), potassium (K), aluminum (Al), magnesium (Mg), combinations thereof, or alloys thereof;

viii) the metal in the anode electrochemically active material and the metal in the cathode electrochemically active material may be the same metal;

ix) the anode electrochemically active material may have a mass that is greater than a mass of the cathode electrochemically active material;

x) the cathode may have a surface area that is smaller than a surface area of the insulator relay layer adjacent the cathode;

xi) the cathode current collector may include copper (Cu);

xii) the relay may include sulfur (S), ferrocene (Fe^sFF^), manganese oxide (MnCL), LixFePCri, where 0 < x < 1, LiMn1.5Nio.5O4, a semiconductor having lower Fermi level than the Fermi level of the active metal in the anode, or combinations thereof;

xiii) the relay may include octasulfur (Ss);

xiv) the insulator relay layer may include particles of the relay;

xv) the insulator relay layer may include an electronic insulator;

xvi) the insulator relay layer may include an electronic conductor in amount of less than 10% weight electronic conductor/ relay;

xvii) the insulator relay layer may include a dielectric polymer/plasticizer; xviii) the insulator relay layer may be adjacent the solid glass electrolyte on the electrolyte side and adjacent the cathode on the cathode side;

xix) the electrolyte side may include a polymer/plasticizer layer adjacent the side of the solid glass electrolyte opposite the anode and adjacent the side of the insulator relay layer opposite the cathode;

xx) the polymer/plasticizer may include a material having a -CºN terminal group;

xxi) the polymer/plasticizer may include succinonitrile (N C-CFL-CFL-

CºN); xxii) the polymer/plasticizer may include electric dipoles that are bonded by dipole-dipole interactions, electric dipoles that are free to rotate, or both;

xxiii) the polymer/plasticizer may include a salt providing a mobile cation that is confined to the polymer/plasticizer;

xxiv) the electrochemical cell may have a life of at least 1000 cycles;

xxv) the electrochemical cell may have an energy density at 25 °C of at least 2500 mAh/g cathode electrochemically active material;

xxvi) the anode may have a surface area and an anode thickness measured in a direction perpendicular to the surface area that is at least 50 pm;

xxvii) the cathode may have a surface area and a cathode thickness measured in a direction perpendicular to the surface area that is at least 50 pm;

xxviii) the solid glass electrolyte may have a surface area and a solid glass electrolyte thickness measured in a direction perpendicular to the surface area that is at least 10 pm.

The present disclosure further provides a battery including any electrochemical cell described above. The battery may contain more than one such sell arrange, for example in series or in parallel. The battery may also include or be physically connected to monitoring and control elements, such as processors or sensors.

The above electrochemical cells and batteries may also be combined with any other features described in this Specification or Figures and such features may be combined with one another unless clearly mutually exclusive.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 1 is a schematic, cross-sectional diagram of an electrochemical cell according to the present disclosure;

FIG. 2 is a schematic, cross-sectional diagram of another electrochemical cell according to the present disclosure;

FIG. 3 is a schematic diagram of a coin cell; FIG. 4 is a graph of a the open circuit voltage of an electrochemical cell containing a stainless steel (SS) anode current collector (which also serves as the electrochemical cell casing), a lithium metal (Li) anode, a solid glass electrolyte containing lithium ion (Li⁺), a succinonitrile (SN) and lithium perchlorate (LiClCri) polymer/plasticizer layer, an octasulfur (Ss) mixed with carbon (C) insulator relay layer, a Li cathode, and a copper (Cu) cathode current collector, along with a stainless steel casing adjacent the Cu (SS/Li/LL-glass/SN+LiOC Ss/C/Li/Cu/SS).

FIG. 5 is a graph of charging of an electrochemical cell containing a stainless steel (SS) anode current collector (which also serves as the electrochemical cell casing), a lithium metal (Li) anode, a solid glass electrolyte containing lithium ion (Li⁺), an octasulfur (Sx) insulator mixed with carbon (C) layer, a Li cathode, and a copper (Cu) cathode current collector, along with a stainless steel casing adjacent the Cu (SS/Li/Li⁺-glass/S8+C/Li/Cu/SS), followed by open circuit voltage.

FIG. 6 is a graph of discharge of an SS/Li/Li⁺- glass/SN+LiCl0₄/S8/C/Li/Cu/SS electrochemical cell.

FIG. 7 is a graph of discharge of a SS/Li/LE-glass/Ss/C/Li/Cu/SS electrochemical cell for approximately three days after one day of charge at a constant current followed by constant voltage.

FIG. 8 is a graph of charge/discharge cycles of a SS/Li/Li⁺- glass/Ss/C/Li/Cu/SS electrochemical cell.

DETAILED DESCRIPTION

The present disclosure relates to an electrochemical cell containing an anode containing an anode current collector, an anode metal, and a solid glass electrolyte containing cations of the anode metal. The electrochemical cell also contains a cathode containing a cathode current collector and a cathode metal. An insulator relay layer is present between the solid glass electrolyte and the cathode metal and/or a polymer/plasticizer and the cathode metal. The cathode metal and the anode metal may be different metals or they may be the same metal, so long as they have different electrochemical potentials (Fermi levels) when arranged in the electrochemical cell.

In some variations, the electrochemical cell may also include a polymer/plasticizer layer. Referring now to FIG. 1 and FIG. 2, an electrochemical cell 10 may include an anode 30, which may include a metal, including a metal alloy. The metal may in particular be an alkali metal, such as lithium (Li), sodium (Na), or potassium (K), or another metal such as aluminum (Al) or magnesium (Mg), combinations thereof, or alloys thereof. The metal in the anode 30 includes at least one metal that is electrochemically active in electrochemical cell 10 and the anode 30 may include more than one metal that is electrochemically active in electrochemical cell 10 if a more complex electrochemical profile, such as the ability to operate at different voltages, is provided. The metal may be in the form of a thin sheet, such as a foil.

The anode 30 may be adjacent to an anode current collector (not shown) on one side and adjacent to the solid glass electrolyte 20 on the other. The anode current collector may also be a metal, such as SS or Cu and, in particular, may be a casing, such as casing 110 shown in FIG. 3. The anode 30 is in electronic contact with the anode current collector, if present. In some electrochemical cells 10, the anode 30 may be used without an anode current collector, for example particularly if the anode 30 includes Al.

The solid glass electrolyte 20 is referred to as glass because it is amorphous, as may be confirmed through the absence of peaks indicating crystalline material in X- ray diffraction.

In particular, the solid glass electrolyte 20 of this disclosure may be a glass containing a metal cation, such as an alkali metal cation, Li⁺, sodium ion (Na⁺), potassium ion (K⁺), or another metal cation such as aluminum ion (Al³⁺) or magnesium ion (Mg²⁺). This metal cation may be a cation of the electrochemically active metal in the anode 30 so that the metal cation can plate onto the anode 30 and the electrochemically active metal in the anode 30 can form the metal cation. The solid glass electrolyte 20 also contains electric dipoles such as A₂X or AX , or MgX or AI2X3 where A = Li, Na, or K and X = oxygen (O) or sulfur (S) or combinations thereof, or another element or electric dipole molecule. Suitable solid glass electrolytes and methods of making them have been previously described in WO2015 128834 (A Solid Electrolyte Glass for Lithium or Sodium Ion Conduction) in

W02016205064 (Water- Solvated Glass/ Amorphous Solid Ionic Conductors), and in WO2018013485 (Self-Charging and/or Self-Cycling Electrochemical Cells) where the solid glass electrolyte composition, methods of making, and methods of incorporating into electrochemical cell disclosures of both are incorporated by references herein.

The solid glass electrolyte 20 contains a dipole additive of the general formula QyXz or Q_y-iXz ^q, or polarized chains that are combinations of coalescent dipoles represented by both general formulas, wherein Q is an alkali metal, such as Li, Na, and K, Mg, or Al, or combination thereof, X is an anion or anion-forming element or compound, including S, O, silicon (Si), or hydroxide (OH ) or a combination thereof , 0<z<3 (more specifically, z is 1, z is 2, and/or z is 3), y is sufficient to ensure charge neutrality of dipoles of the general formula A_yX_z, or a charge of -q of dipoles of the general formula A_y-iX_z ^q (more specifically, 0<y<3, or y is 1, y is 2, or y is 3, or combinations thereof), and l<q<3 (more specifically, q is 1, q is 2, or q is 3, or combinations therof).

Mixtures of dipole additives with the general formulas A_yX_z or A_y-iX_z ^q may be particularly likely to be present after the initial charge or initial cycle of the electrochemical cell 10 because the additives may lose one or more metal cations, while still retaining at least one metal cation bound to the anion and thus still retaining its dipole nature.

Specific dipole additives may have the formula A₂S or AS , or a combination of additives represented by both general formulas, wherein A is Li, Na, and/or K, such as LLS or a mixture of LLS and LiS .

Other specific dipole additives may have the formula A2O or AO , or a combination of additives represented by both general formulas, wherein A is Li, Na, and/or K, such as L12O or a mixture of L12O and LiO .

Other specific dipole additives may be ferroelectric condensate molecules of the above dipoles in which A is Li, Na, or K and X is O, S, or a combination thereof.

Still other specific dipole additives may be polymeric larger dipole molecules or compositions, such as a paper or other cellulose with negative groups, such as hydroxyl (OH ) groups, or polytetrafluoroethylene (PTFE).

Other additives may increase the dielectric constant of the solid glass electrolyte 20. For example, other additives may include be crystalline materials with high dielectric constants, particularly a dielectric constant such as at least 5000 or at least 7000. Suitable crystalline materials include BaTiCh, SrTiCh, CaCu3Ti₄0i2, and/or Ti02.

The presence of the electric dipoles gives the solid glass electrolyte 20 a high dielectric constant, such as at least 5000 or at least 7000. The electric dipoles may also be active in promoting a self-charge and self-cycling phenomenon.

In addition, the solid glass electrolyte 20 is not reduced on contact with the metal in the anode 30. Therefore, there is no formation of a passivating solid- electrolyte interphase (SEI) at the interface with of solid glass electrolyte 20 with the anode 30.

Also, the surface of the solid glass electrolyte 20 is wet by the

electrochemically active metal, such as the alkali metal, of the anode 30, which allows dendrite-free plating of the metal to the anode 30 from the solid glass electrolyte 20. This provides a low resistance to the transfer of metal cations across an

electrode/electrolyte interface over at least a thousand, at least two thousand, or at least five thousand charge/discharge cycles.

The solid glass electrolyte 20 may have a large dielectric constant, such as a relative permittivity (sr) of 10² or higher. The solid glass electrolyte 20 may have an ionic conductivity sί for at least one metal cation, typically the cation of the electrochemically active metal in the anode 30, of at least 10 ² S/cm at 25 °C. This conductivity is comparable to the ionic conductivity of the flammable conventional organic-liquid electrolytes used in Li-ion batteries. The resistance to cation transport in a solid electrolyte is Thickness/ [sί_c Area], where sί is the cation conductivity of the electrolyte and Thickness/ Area is the ratio of the electrolyte thickness to its area. Typically, the solid glass electrolyte 20 will have a Thickness/ Area that is less than 1, less than 0.5, less than 0.25, less than 0.1, or less than 0.5. The sί of electrochemical cell 10 can be determined from the Thickness/ Area, when the resistance is measured, for example by making and electrical impedance spectroscopy measurement or a charge/discharge measurement using a symmetric cell with two electrodes of the alkali metal working ion.

The solid glass electrolyte 20 is electronically insulating due to a sufficiently large energy-state gap and may be non-flammable. The solid glass electrolyte 20 may be formed by transforming a crystalline electronic insulator containing the metal cation of interest or its constituent precursors (typically containing the working ion bonded to O, OH , and/or a halide) into a cation conducting glass/amorphous solid. This process can take place in the presence of a dipole additive as well.

The solid glass electrolyte 20 may be in the form of a membrane, which is typically mechanically robust.

The electrochemical cell 10 further includes an insulator relay layer 40 which is adjacent to the solid glass electrolyte 20 on the side opposite the anode 30. The insulator relay layer 40 is also adjacent to the cathode 50 on the side opposite the solid glass electrolyte 20. The insulator relay layer 40 is electronically insulating, so the Fermi level of the cathode 50 remains similar to the Fermi level of the relay insulator layer 40 in electrochemical cell 10, even during charge and discharge.

In addition to being electronically insulating, the insulator relay layer 40 also does not conduct cations, or conducts them very poorly (for example, it may have an ionic conductivity for cations in the solid glass electrolyte 20 of 10 ⁷ S/cm or less at 25 °C). As a result, the electrolyte side of the electrochemical cell 10 is also ionically insulated from the cathode side of the electrochemical cell 10. Cations, such as cations of the electrochemically active metal in anode 30, do not substantially pass from the solid glass electrolyte 20 through the insulator relay layer 40 to the cathode 50. Instead, the insulator relay layer 40 relays charge without allowing physical movement of ions. If the insulator relay layer also contains carbon (C), the cations of the electrochemically active metal in anode 30 may plate on the carbon’s surface during discharge.

The insulator relay layer 40 may include as a relay any compound or element that, when present in the insulator relay layer 40, has a Fermi level lower than the Fermi level of the anode 30.

The relay may include an element, such a sulfur (S), a molecule, such as ferrocene (Fe(C5H5)₂) or manganese oxide (MnCk), a variable compound, such as lithium iron phosphate (LixFePCri, where 0 < x < 1), lithium manganese nickel oxide (LiMn1.5Nio.5O4) or a semiconductor having lower Fermi level than the Fermi level of the active metal in the anode 30, or combinations thereof. In particular, the relay may include octasulfur (Ss).

Due to the solid nature of the solid glass electrolyte 20, it may block any movement of the relay or any by-products thereof (such as poly sulfides) to the anode. As a result, materials know to“poison” anodes by forming layers on them or reacting with anode materials may be used in the insulator relay layer 40 because they are excluded from the anode 30 by the solid glass electrolyte 20.

The insulator relay layer 40 may also contain elemental carbon (C), such as carbon particles, another electronic conductor, or combinations thereof. Because the C or other electronic conductor is electronically conductive, it may only be present in limited amounts in order for the electrochemical cell 10 to have a stable voltage. For example, the amount of carbon (C) or any other electronic conductor in the insulator relay layer 40 may be limited to less than 10%, less than 5%, less than 2%, or less than 0.5% weight C/weight of the relay. Alternatively, or in addition, the insulator relay layer 40 may contain sufficiently low levels of C or any other electronic conductor for the electronic conductivity of insulator relay layer 40 to be less than 2%.

The insulator relay layer 40 may contain particles of the relay and any electronic conductor, if present, formed into a sheet or film by another material, such as a dielectric polymer/plasticizer, such as a polymer/plasticizer having a dielectric constant of 50. The polymer/plasticizer may be the same type as may be used in the polymer/plasticizer layer 70 as described below in relation to FIG. 2. The insulator relay layer 40 may also be coated onto the solid glass electrolyte 20, the cathode 50 (and any exposed cathode current collector 60, if present), or the polymer/plasticizer layer 70, if present. The relay, the electronic conductor, or both may be homogenously dispersed in such a sheet or film.

The Fermi level of the relay in the insulator relay layer 40, as compared to the Fermi level of the electrochemically active metal in the anode 30, sets the voltage (V) of the electrochemical cell 10.

The cathode 50 may include as an electrochemically active material any element or compound that has a chemical potential lower than the Fermi level of the electrochemically active metal in the anode 30 and higher than the Fermi level of the relay in the insulator relay layer 40. In particular, the cathode 50 may contain a metal a metal alloy, or combinations thereof. In particular the electrochemically active metal in the cathode 50 may be the same metal as the electrochemically active metal in the anode 30. The metal may include a cathode electrochemically active metal that is able to pass charge from the relay and thus form the metal or its cation as the electrochemical cell 10 is charged and discharged. The metal may, in particular, be and alkali metal, such as Li, Na, or K, or Mg or Al. Although pure metal may be used in the cathode 50, Na/Li alloys and Mg alloys are also particularly useful in the cathode 50. The capacity of the electrochemical cell 10 may be maximized if the anode electrochemically active metal and the cathode electrochemically active metal are the same metal, such as Li, Na, K, Mg, or Al.

The cathode 50 may be in the form of a thin sheet, such as a foil.

The use of the same metal as the electrochemically active metal in both the anode 30 and the cathode 50 is possible because the same metal has a higher Fermi level in the anode 30 and a lower Fermi level in the cathode 50. Due to the ionic separation of the cathode side and the electrolyte side of the electrochemical cell 10 by the insulator relay layer 40, during operation of the electrochemical cell 10, electric double-layer capacitors (ELDCs) form throughout the electrochemical cell 10 with charges as shown in FIG. 1 and FIG. 2.

The electrochemical cell 10 may also include a cathode current collector 60, such as a layer of another metal or metal alloy that has a Fermi level lower than that of the electrochemically active material of the cathode 50. For example, the cathode current collector 60 may include Cu or a Cu alloy. The current collector is adjacent to the cathode 50 on the side opposite the insulator relay layer 40. The cathode current collector 60 may be in the form of a thin sheet, such as a foil.

The surface areas of the cathode 50 and the cathode current collector 60 may be similar, as shown in FIG. 2. Alternatively, the surface area of the cathode 50 may be less than that of the cathode current collector 60, such as 10% less, 25% less, or 50% less, as illustrated in FIG. 1 and FIG. 3. If the surface area of the cathode 50 is less than that of the cathode current collector 60, but the insulator relay layer 40 has a surface area similar to that of the cathode current collector 60, then in some places the insulator relay layer 40 will be adjacent to the cathode current collector 60. The electrochemical cell 10 may also contain a polymer/plasticizer layer 70, as shown in FIG. 2. The polymer/plasticizer layer 70 may be adjacent to the solid glass electrolyte 20 on one side and the insulator relay layer 40 and also the exposed portion of the cathode current collector 60, if it has a surface area greater than the surface area of the insulator relay layer 40. The polymer/plasticizer layer 70 may coat the insulator relay layer 40 (and also the exposed portion of the cathode current collector 60, if present), or it may be in the form of a free-standing membrane.

The polymer/plasticizer layer 70 may be a dielectric material, having a dielectric constant of at least 50, between 50 and 100, between 50 and 500, between 50 and 1,000, between 50 and 5,000, between 50 and 10,000, between 50 and 20,000, between 100 and 500, between 100 and 1,000, between 100 and 5,000, between 100 and 10,000, or between 100 and 20,000. The polymer/plasticizer layer 70 may be permeable to the cation of the anode electrochemically active material, another cation in the solid glass electrolyte 20, or both, so that at least one cation from the anion side of the electrochemical cell 10 can reach the insulator relay layer 40.

The polymer/plasticizer layer 70 may include any organic polymer or other organic material that does not react with cations in the solid glass electrolyte 20 and is not oxidized by the insulator relay layer 40 during cycling of the electrochemical cell 10, or whose oxidation by the insulator relay layer 40 during cycling of the electrochemical cell 10 is sufficiently low for the electrochemical cell 10 to have an average life of at least 200 cycles, at least 1000 cycles, or at least 5000 cycles.

Suitable materials for polymer/plasticizer layer 70 include materials having - CºN terminal groups, including and similar to those in succinonitrile (NºC-CH2-CH2- CºN).

The polymer/plasticizer layer 70 may contain electric dipoles that are bonded by dipole-dipole interactions and/or electric dipoles that are free to rotate.

The polymer/plasticizer layer 70 may contain a salt providing a mobile cation that is confined to the plasticizer, such as lithium perchlorate (LiClCri).

The surface area of the insulator relay layer 40 may be the same or larger than the surface area of the cathode 50 so that the insulator relay layer 40 may separate the electrolyte side of the electrochemical cell 10 from the cathode side of the electrochemical cell 10. The surface areas of one, more than one, of the other components of the electrochemical cell 10, including the anode current collector, if present, the anode 30, the cathode 50, and the cathode current collector 60 may be equal to or smaller than the surface area of insulator relay layer 40. The electrochemical cell 10 may be in a casing or may contain other components in order to seal the electrochemical cell 10 and to allow the insulator relay layer 40 to separate the electrolyte side of the electrochemical cell 10 from the cathode side of the electrochemical cell.

Each component of the electrochemical cell 10 may have thickness measured in the direction perpendicular to the surface area. The thickness of each component may vary by less than 25%, less than 10%, less than 5%, less than 1%, or less than 0.5%. Both the anode 30 and the cathode 50 may be substantially thicker than in many traditional electrochemical cells. For example, either the anode 30 or the cathode 50, or both may have thickness of at least 20 pm, at least 100 pm, at least 250 pm, or at least 500 pm.

The solid glass electrolyte may have a thickness of at least 10 pm, at least 25 pm, at least 50 pm, at least 75 pm, or at least 100 pm.

The mass of the cathode electrochemically active material in the cathode 50 may be greater than the mass of the anode electrochemically active material in the 30. In particular, it may be 5/3 of the mass of the anode 30 or more. This allows the electrochemical cell 10 to have an increased capacity as compared to electrochemical cells with lower masses of electrochemically active material in the cathode because extra metal can be plated from the solid glass electrolyte 20 during charge.

In general, electrochemical cells 10 containing solid glass electrolytes 20 operate by transporting electronic charge between the electrodes (anode 30 and cathode 50) using an external circuit (designated by e and arrows in FIG. 1 and FIG. 2). Mobile cation displacements transport ionic charge between the electrodes largely by small displacements at the electrode interfaces, where plating and stripping occur. When these small displacements occur, a small electric dipole displacement occurs within the solid glass electrolyte 20 due to the presence of both mobile cations and slower-moving electric dipoles in the solid glass electrolyte 20. These electric dipole displacements largely substitute for cation transport across the solid glass electrolyte 20, as typically occurs in liquid electrolytes. This allows very fast charge and discharge of the electrochemical cell 10, as well as long cycle-life.

During operation of the electrochemical cell 10, the narrow band of surface states present in the relay are partially vacated to produce a positive charge in the insulator relay layer 40 adjacent to the solid glass electrolyte 20 or polymer/plasticizer layer 70 that mirrors a negative charge on the opposite side of the insulator relay layer 40 where it is adjacent to the cathode 50, as illustrated in FIG. 1 and FIG. 2. The negative charge on the electrolyte side of the insulator relay layer 40 or polymer/plasticizer layer 70 is the result of mobile cation vacancies caused by a mobile cation surplus where the solid glass electrolyte 20 is adjacent to the anode 30.

During discharge of the electrochemical cell 10, the occupancy of surface states of the relay varies with the relative rates of metal ion plating on the cathode 50 and the arrival of electrons to the cathode 50 from the anode 30 via an external circuit. Once the surfaces states are filled, the relay is reduced, at which point the energy difference between the cathode 50 and the anode 30 changes more rapidly with state of electrochemical cell charge. Once all of the relay is reduced, the discharge is complete.

The capacity of the electrochemical cell 10, therefore, depends on the discharge current (Idis) and the number of relay molecules per unit area in the insulator relay layer 40, as well as the amount of metal (or other electrochemically active material) in the cathode 50. The rate of plating or stripping of metal ion to or from the cathode 50 relative to the discharge current (Idis) and the number of relay molecules determine the rate of voltage decrease at the onset of filling the relay surface states. The cathode 50 is ultimately oxidized and reduced during charge and discharge, and thus also determines the capacity of electrochemical cell 10.

Electrochemical cell 10 may have an energy density at 25 °C of at least 2500 mAh/g of cathode 50, at least 2750 mAh/g of cathode 50, or at least 3000 mAh/g of cathode 50. g of cathode 50 may represent the total mass of cathode 50, or only the mass of the electrochemically active material in cathode 50.

Electrochemical cells 10 of the present disclosure may be used in batteries.

Such batteries may be simple batteries containing few components other than the electrochemical cell 10 and a casing or other simple mechanical features. Such batteries may be in standard battery formats, such as coin cell, or standard pouch, jellyroll or prismatic cell formats. They may also be in more tailored formats, such as tailored prismatic cells.

Electrochemical cells 10 of the present disclosure may also be used in more complex batteries, such as batteries containing complex circuitry and a processor and memory computer-implemented monitoring and regulation.

Regardless of simplicity, complexity, or format, all batteries using electrochemical cells 10 of the present disclosure may exhibit improved safety, particularly a lower tendency to catch fire when damaged, as compared to batteries with li qui d el ectrolyte s .

In addition, batteries according to the present disclosure may be multi-cell batteries, containing at least two or at least five electrochemical cells 10 of the present disclosure. Cells in multi-cell batteries may be arranged in parallel or in series.

By way of example, electrochemical cells 10 of the present disclosure may be used in portable, hand-held and/or wearable electronic device, such as a phone, watch, or laptop computer; in a stationary electronic device, such as a desktop or mainframe computer; in an electric tool, such as a power drill; in an electric or hybrid land, water, or air-based vehicle, such as a boat, submarine, bus, train, truck, car, motorcycle, moped, powered bicycle, airplane, drone, other flying vehicle, or toy versions thereof; for other toys; for energy storage, such as in storing electricity from wind, solar, wave, hydropower, or nuclear energy and/or in grid storage, or as a stationary power store for small-scale use, such as for a home, business, or hospital.

FIG. 3 is a schematic diagram of an example coin cell 100 including an electrochemical cell 10 of the present disclosure. The coin cell 100 includes a casing 170, which may be stainless steel or another electronically conductive material or an electronically insulating material with electronically conductive contacts. The casing 170 may serve as an anode current collector in alternative configurations lacking anode current collector 110 (not shown). The coin cell 100 also includes an anode current collector 110, an anode sheet 130, which may include an anode 30 and, optionally, an anode current collector. The coin cell 100 includes a solid glass electrolyte sheet 120, which may include a solid glass electrolyte 20. The solid glass electrolyte sheet 120 may include the solid glass electrolyte 20 in a paper matrix or the solid glass electrolyte 20 with a polymer or plasticizer present for ease of assembly. The coin cell 100 further includes an insulator relay sheet 140, which includes an insulator relay layer 40. The insulator relay sheet 140 may also include a polymer or plasticizer. As shown, the insulator relay sheet may have a larger surface area than the solid glass electrolyte sheet 120. The coin cell 100 additionally includes a cathode current collector sheet, 160, which may include an cathode current collector 60. Finally, the coin cell 100 includes a spring 150 to help maintain the interface of the sheets. The coin cell 100 may contain multiple iterations of sheets 110, 120, 130, 140, and 160, with an electronically insulative separator between then (not shown). One of ordinary skill in the art will appreciate that coin cells are frequently constructed as test cells and that other batteries may be constructed using methods known in the art to adapt finding in coin cells to other types of batteries.

EXAMPLES

The following examples are provided to further illustrate the principles and specific aspects of the disclosure. They are not intended to and should not be interpreted to encompass the entire breath of all aspects of the disclosure.

Two example electrochemical cells were constructed according to the principles and designs contained herein. One electrochemical cell (SS/Li/Li⁺- glass/SN+LiO04/S8/C/Li/Cu/SS). contained a polymer/plasticizer layer and the other (SS/Li/LE-glass/Ss/C/Li/Cu/SS) did not. The cells were coin cells with a structure similar to that shown in FIG. 3.

FIG. 4 is a graph of the open circuit voltage of the SS/Li/Li⁺- glass/SN+LiC10₄/S8/C/Li/Cu/SS electrochemical cell. The cell showed self-cycling with a period of 8 minutes, similar to what was observed with a cell using aluminum as the anode and copper the as cathode (data now shown).

FIG. 5 is a graph of charging of the S S/Li/Li ⁺-gl as s/Ss/C/Li/Cu/SS electrochemical cell, followed by open circuit voltage. The measured potential at the open circuit voltage is the potential of non-reduced Sx vs. Li (2.34 V to 2.65V), showing that the relay and the anode electrochemically active material set the voltage of the electrochemical cell.

FIG. 6 is a graph of discharge of the SS/Li/Li⁺- glass/SN+LiC10₄/S8/C/Li/Cu/SS electrochemical cell. A plateau potential of 2.2-2.0 V was observed showing that the voltage was established by the anode and the relay. The discharge curve also shows that Li might have been plated on the S-relay and that S8 might have been reduced or that the internal resistance was responsible by a voltage drop of 0.2-0.4 V in comparison to the expected voltage of 2.34-2.6 V. The initial voltage plateau at 2.3 V that is typical of a Li-S traditional cell discharge curve is not visible which is in opposition with the assumption that Sx might have been reduced.

FIG. 7 is a graph of discharge of the SS/Li/LE-glass/Ss/C/Li/Cu/SS electrochemical cell for approximately three days after one day of charge at a constant current followed by constant voltage. Because discharge capacity was around three times charge capacity, it is likely that lithium from the electrolyte might have been plated on the carbon at the insulator relay layer and that Sx might have been reduced forming LLSs and even LbS.

FIG. 8 is a graph of charge/discharge cycles of the SS/Li/LE-glass/Ss/C/Li/Cu/SS electrochemical cell.

The electrochemical cells were also effective to power a red light-emitting diode (LED), demonstrating an output voltage of at least 1.5 V and an output current of at least 100 mA, at least 500 mA, 1 mA or 5 mA.

The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments which fall within the true spirit and scope of the present disclosure. Thus, to the maximum extent allowed by law, the scope of the present disclosure is to be determined by the broadest permissible interpretation of the following claims and their equivalents and shall not be restricted or limited by the foregoing detailed description.

Claims

1. An electrochemical cell comprising:

an electrolyte side comprising:

an anode comprising an anode electrochemically active material comprising a metal; and

a solid glass electrolyte adjacent a side of the anode, wherein the solid glass electrolyte comprises a cation of the metal in the anode electrochemically active material and an electric dipole having the formula A₂X or AX , or MgX or AI2X3 wherein A = Li, Na, or K and X = oxygen (O) or sulfur (S) or combinations thereof;

a cathode side comprising:

a cathode comprising a cathode electrochemically active material; and a cathode current collector adjacent a side of the cathode; and an insulator relay layer adjacent the electrolyte side on one side of the insulator relay layer and adjacent the cathode side on the other side of the insulator relay layer, wherein the insulator relay layer ionically separates the electrolyte side and the cathode side, and wherein the insulator relay layer comprises a relay,

wherein the anode has a Fermi level higher than ta Fermi level of the relay and the Fermi level of relay sets a Fermi level of the cathode.

2. The electrochemical cell of Claim 1, wherein the metal in the anode electrochemically active material is lithium (Li), sodium (Na), potassium (K), aluminum (Al), magnesium (Mg), combinations thereof, or alloys thereof.

3. The electrochemical cell of Claim 1, wherein the electrolyte side further comprises an anode current collector adjacent the anode on a side opposite the solid glass electrolyte.

4. The electrochemical cell of Claim 3, wherein the anode current collector comprises copper (Cu) or stainless steel (SS).

5. The electrochemical cell of Claim 1, wherein the solid glass electrolyte further comprises a dipole additive having a general formula Q_yX_z or Q_y-iX_z ^q, or polarized chains that are combinations of coalescent dipoles represented by both general formulas, wherein Q is Li, Na, K, Mg, or Al, or combination thereof, X is S, O, silicon (Si), or hydroxide (OH ) or a combination thereof , 0<z<3, 0<y<3 and l<q<3.

6. The electrochemical cell of Claim 1, wherein the solid glass electrolyte has a dielectric constant of at least 5000.

7. The electrochemical cell of Claim 1, wherein the cathode electrochemically active material comprises a metal.

8. The electrochemical cell of Claim 7, wherein the metal in the cathode electrochemically active material is lithium (Li), sodium (Na), potassium (K), aluminum (Al), magnesium (Mg), combinations thereof, or alloys thereof.

9. The electrochemical cell of Claim 7, wherein the metal in the anode electrochemically active material and the metal in the cathode electrochemically active material are the same metal.

10. The electrochemical cell of Claim 1, wherein the anode electrochemically active material has a mass that is greater than a mass of the cathode electrochemically active material.

11. The electrochemical cell of Claim 1, wherein the cathode has surface area that is smaller than a surface area of the insulator relay layer adjacent the cathode.

12. The electrochemical cell of Claim 1, wherein the cathode current collector comprises copper (Cu).

13. The electrochemical cell of Claim 1, wherein the relay comprises sulfur (S), ferrocene (FejCsFL^), manganese oxide (MnC ), Li_xFeP0₄, where 0 < x < 1, LiMn1.5Nio.5O4, a semiconductor having lower Fermi level than the Fermi level of the active metal in the anode, or combinations thereof.

14. The electrochemical cell of Claim 1, wherein the relay comprises octasulfur (Ss).

15. The electrochemical cell of Claim 1, wherein the insulator relay layer comprises particles of the relay.

16. The electrochemical cell of Claim 1, wherein the insulator relay layer is an electronic insulator.

17. The electrochemical cell of Claim 1, wherein the insulator relay layer further comprises an electronic conductor in amount of less than 10% weight electronic conductor/ relay.

18. The electrochemical cell of Claim 1, wherein the insulator relay layer further comprises a dielectric polymer/plasticizer.

19. The electrochemical cell of Claim 1, wherein the insulator relay layer is adjacent the solid glass electrolyte on the electrolyte side and adjacent the cathode on the cathode side.

20. The electrochemical cell of Claim 1, wherein the electrolyte side further comprises a polymer/plasticizer layer adjacent the side of the solid glass electrolyte opposite the anode and adjacent the side of the insulator relay layer opposite the cathode.

21. The electrochemical cell of Claim 20, wherein the polymer/plasticizer comprises a material having a -CºN terminal group.

22. The electrochemical cell of Claim 21, wherein the polymer/plasticizer comprises succinonitrile (NºC-CH2-CH2-CºN).

23. The electrochemical cell of Claim 20, wherein the polymer/plasticizer comprises electric dipoles that are bonded by dipole-dipole interactions, electric dipoles that are free to rotate, or both.

24. The electrochemical cell of Claim 20, wherein the polymer/plasticizer comprises a salt providing a mobile cation that is confined to the polymer/plasticizer.

25. The electrochemical cell of Claim 1, wherein the electrochemical cell has a life of at least 1000 cycles.

26. The electrochemical cell of Claim 1, wherein the electrochemical cell has an energy density at 25 °C of at least 2500 mAh/g cathode electrochemically active material.

27. The electrochemical cell of Claim 1, wherein the anode has a surface area and an anode thickness measured in a direction perpendicular to the surface area, and wherein the anode thickness is at least 50 pm.

28. The electrochemical cell of Claim 1, wherein the cathode has a surface area and a cathode thickness measured in a direction perpendicular to the surface area, and wherein the cathode thickness is at least 50 pm.

29. The electrochemical cell of Claim 1, wherein the solid glass electrolyte has a surface area and a solid glass electrolyte thickness measured in a direction perpendicular to the surface area, and wherein the solid glass electrolyte thickness is at least 10 pm.

30. A battery comprising an electrochemical cell as described in any of

Claims 1-29.