CN108448063A - A kind of protection method of metal negative electrode of alkali metal secondary battery - Google Patents

Abstract

The present invention relates to a kind of guard methods of alkali metal secondary battery metal negative electrode；Alkali metal secondary battery includes the battery as cathode with lithium metal, metallic sodium and metallic potassium；Guard method achievees the purpose that protect alkali metal cathode by designing one layer of adding layers in battery alkali metal negative terminal surface.By this simple method, under the premise of not changing alkali metal battery conventional fabrication processes, dendrite of the alkali metal cathode in battery charge and discharge process can be efficiently controlled to be formed, improve the safety of battery, and significantly promote the charge-discharge velocity and cycle life of battery metal cathode, the overpotential of battery cathode is reduced, there is high practical value.

Description

A kind of protection method of metal negative electrode of alkali metal secondary battery

technical field

The invention relates to the technical fields of electrochemistry and electric energy storage, in particular to a method for protecting metal negative electrodes of alkali metal secondary batteries.

Background technique

Due to its high theoretical capacity and low potential, metal lithium anodes have greater advantages than carbon-based anodes currently used in lithium-ion batteries. However, there are still some thorny problems to be solved urgently. Dendrites will be generated on the surface of lithium metal anode during the charging and discharging process, and the growth of lithium dendrites threatens the safe use of lithium metal batteries. Similarly, the anode interfaces of sodium metal batteries and potassium metal batteries are more unstable than metallic lithium and face more severe safety issues.

Recent research on the protection of lithium metal anodes mainly focuses on the optimization of the electrolyte, the modification of the solid electrolyte membrane (SEI membrane), the improvement of the separator, and the structural design of the current collector. For example: adding fluorine-containing additives to the electrolyte makes it easier to form a stable solid-state electrolyte film (SEI film) on the surface of the negative electrode to inhibit the formation of lithium dendrites; or artificially create an artificial solid-state electrolyte film (SEI film) on the surface of metal lithium ) to achieve the purpose of stabilizing metal lithium; or perform some functional treatments on the battery separator to increase the mechanical strength of the separator, so that the generated lithium dendrites are not easy to pierce the separator and cause short circuit; Functional design, such as converting the traditional two-dimensional current collector to a three-dimensional current collector to alleviate the dendrite formation of the negative electrode. These methods are effective in protecting metal negative electrodes and improving battery stability, but most methods have high preparation costs for lithium metal negative electrodes, complex methods, difficult operations, incompatible with existing metal lithium manufacturing processes, and for The same approach does not work for the same family of sodium and potassium metal batteries.

Contents of the invention

In order to solve a series of problems existing in the alkali metal negative electrode of the prior art during the secondary battery cycle, the present invention proposes a simple and effective protection method for the alkali metal negative electrode. An additive layer is placed on the surface of the alkali metal negative electrode of the battery. Disperses the current density on the surface of the alkali metal negative electrode, providing a larger surface area for the deposition and dissolution of lithium ions, so that the alkali metal of the negative electrode does not produce dendrites that can pierce the separator during the cycle, and at the same time, it is the alkaline metal negative electrode in the cycle process. A certain space is provided for the volume expansion generated in the electrode, and the effect of protecting the alkali metal negative electrode is achieved.

The invention discloses a method for protecting the metal negative pole of an alkali metal secondary battery. The protection method for the metal negative pole of the alkali metal secondary battery is to arrange an additive layer on the surface of the metal negative pole of the alkali metal secondary battery to realize the metal negative pole of the alkali metal secondary battery The protection of the metal negative electrode achieves the purpose of improving the cycle stability and cycle life of the metal negative electrode and reducing the overpotential during the cycle of the metal negative electrode.

In the present invention, the structure of the added layer is a film structure or a thin net structure.

In the present invention, the material of the added layer includes one or more of carbon materials, metals, compounds, and conductive polymers, and the material of the added layer refers to the material used to form the added layer.

In the present invention, the metal includes, aluminum, stainless steel, copper; the carbon material includes carbon fiber, carbon tube, graphene; the compound includes oxide, sulfide, nitride, phosphide, carbide, boride One or more; preferably, the carbon material includes carbon paper, carbon cloth, 3D graphene; the metal includes metal nickel mesh, metal aluminum mesh, stainless steel mesh, metal copper mesh; the oxide is transition Metal oxides; the sulfides are transition metal sulfides.

Further preferably, the material of the added layer is a single carbon material, metal or conductive polymer; or the material of the added layer is a composite material formed of a carbon material and a compound, and the added layer of the present invention has conductivity.

In the present invention, the alkali metal includes lithium, sodium or potassium.

The invention discloses an alkali metal secondary battery, which comprises a positive electrode and an alkali metal negative electrode. The surface of the alkali metal negative electrode is provided with an additive layer; the structure of the additive layer is a film structure, a network structure or a 3D structure; the additive layer The materials include one or more of carbon materials, metals, compounds, and conductive polymers; the metals include aluminum, stainless steel, and copper; the carbon materials include carbon fibers, carbon tubes, and graphene; the compounds include oxide One or more of compounds, sulfides, nitrides, phosphides, carbides, borides; preferably the added layer is carbon paper, carbon cloth, 3D graphene, metal nickel mesh, metal aluminum mesh, stainless steel mesh , metal copper mesh, conductive polymer film; or the added layer is a composite material formed of carbon tubes or graphene, transition metal sulfides, and transition metal oxides; carbon paper is the most preferred, and the most excellent technical effect can be obtained.

The invention discloses a preparation method of an alkali metal secondary battery. An additive layer is arranged on the surface of the metal negative electrode of the alkali metal secondary battery, and the alkali metal secondary battery is composed of conventional components of the alkali metal secondary battery; the structure of the additive layer It is a film structure, a network structure or a 3D structure; the material of the added layer includes one or more of carbon materials, metals, compounds, and conductive polymers; the metal includes, aluminum, stainless steel, and copper; the carbon material Including carbon fibers, carbon tubes, graphene; the compound includes one or more of oxides, sulfides, nitrides, phosphides, carbides, borides; preferably the added layer is carbon paper, carbon cloth, 3D graphene, metal nickel mesh, metal aluminum mesh, stainless steel mesh, metal copper mesh, conductive polymer film; or the added layer is a composite material formed of carbon tubes or graphene, transition metal sulfides, and transition metal oxides; The most preferred carbon paper can obtain the most excellent technical effect.

The invention also discloses the application of the added layer in protecting the metal negative electrode of the alkali metal secondary battery or in the preparation of the alkali metal secondary battery; the structure of the added layer is a film structure or a thin net structure; the material of the added layer includes carbon One or more of materials, metals, compounds, and conductive polymers; the metals include aluminum, stainless steel, and copper; the carbon materials include carbon fibers, carbon tubes, and graphene; the compounds include oxides and sulfides , nitride, phosphide, carbide, boride; preferably the added layer is carbon paper, carbon cloth, 3D graphene, metal nickel mesh, metal aluminum mesh, stainless steel mesh, metal copper mesh 1. Conductive polymer film; or the added layer is a composite material formed of carbon tubes or graphene, transition metal sulfides, and transition metal oxides; most preferably carbon paper, which can obtain the most excellent technical effect.

The present invention improves the battery structure of the traditional positive electrode material/diaphragm/alkali metal negative electrode to the battery structure of positive electrode material/diaphragm/addition layer/alkali metal negative electrode, and the method for adding the addition layer of the alkali metal secondary battery is to directly add the addition layer Sandwiched between the negative alkali metal and the battery separator or for batteries without a separator, the additive layer directly covers the surface of the negative alkali metal during battery assembly.

The method of the present invention is applicable to a wide range of secondary battery systems, and other conventional components of the battery except the added layer can be arbitrarily matched; the conventional components of the alkali metal secondary battery can include: battery positive electrode material paired with the alkali metal negative electrode, battery diaphragm type, electrolyte , electrolyte system, battery type. for example:

Battery positive electrode materials include lithium battery positive electrode materials: lithium iron phosphate positive electrode materials; lithium cobalt oxygen, lithium manganese oxygen, lithium nickel oxygen binary composite positive electrode materials; lithium nickel manganese oxygen ternary composite positive electrode materials; lithium sulfur battery sulfur composite positive electrode materials ; Oxygen and catalyst composite materials for lithium-oxygen batteries and lithium-air batteries, as well as cathode materials for sodium batteries and cathode materials for potassium batteries.

Battery separator, including PP film; PE film; PP/PE film; PP/PE/PP film; glass cellulose separator; non-woven film, etc.

Electrolytes, including lithium/sodium/potassium bistrifluoromethanesulfonimide (Li/Na/KTFSI); lithium/sodium/potassium trifluoromethanesulfonimide (Li/Na/KFSI); lithium hexafluorophosphate (Li/Na/ KPF6); lithium/sodium/potassium perchlorate (Li/Na/KClO4); lithium/sodium/potassium tetrafluoroborate (Li/Na/KBF4); lithium/sodium/potassium bisoxalate borate (Li/Na/KBOB) Wait.

Electrolyte system, including carbonate organic electrolyte system; ether organic electrolyte system; water electrolyte; solid electrolyte system, etc.

Electrolytic battery types, including button batteries, pouch batteries, cylindrical batteries, etc.

Due to the application of the above-mentioned technical solution, the present invention has the following advantages compared with the prior art:

1. The method for protecting the alkali metal negative electrode provided by the present invention has a significant protective effect, and has incomparable advantages in prolonging the cycle life of the metal negative electrode and reducing the overpotential of the metal negative electrode.

2. With the method for protecting the alkali metal negative electrode provided by the present invention, even under the condition of extremely high current density, the negative electrode metal can still cycle thousands of times stably and efficiently.

3. Compared with most of the current methods that can only realize the protection of metal lithium negative electrodes, the protection method for protecting alkali metal negative electrodes provided by the present invention can not only be applied to metal lithium negative electrodes, but also can be used for metal sodium negative electrodes and metal lithium negative electrodes of the same family. Potassium negative electrode has a wide range of applications.

4. The method for protecting the alkali metal negative electrode provided by the present invention is applicable to different battery systems, battery models, and a wide range of applications.

5. The method for protecting the alkali metal negative electrode provided by the present invention is simple and can achieve significant protection effect without changing the existing alkali metal manufacturing process.

Description of drawings

Fig. 1 is the cycle number-voltage graph of the metal lithium symmetric battery protected by carbon paper in embodiment one;

Fig. 2 is the cycle number-voltage graph of the metal lithium symmetric battery protected by carbon paper in embodiment two;

Fig. 3 is the cycle number-voltage graph of the metal lithium symmetric battery protected by carbon paper in embodiment three;

Fig. 4 is the cycle number-voltage graph of the metal lithium symmetric battery of the metal aluminum mesh in embodiment four;

Fig. 5 is the cycle number-voltage graph of the metal sodium symmetric battery protected by carbon paper in embodiment five;

Fig. 6 is the cycle number-voltage graph of the metal sodium symmetric battery protected by carbon paper in embodiment six;

Fig. 7 is the cycle number-voltage graph of the metal potassium symmetric battery protected by carbon paper in embodiment seven;

Fig. 8 is the cycle number-voltage graph of the metal lithium symmetric battery protected by the carbon paper in Comparative Example 1;

Fig. 9 is the number of cycle-voltage curves of the metal sodium symmetric battery protected by carbon paper in Comparative Example 2;

Fig. 10 is the cycle number-voltage curve of the metal potassium symmetric battery protected by carbon paper in Comparative Example 3.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined arbitrarily with each other.

Example 1 Metal Lithium Symmetrical Battery Protected by Carbon Paper at Low Current Density in Ether Electrolyte System

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is ether electrolyte, the solute is lithium bistrifluoromethanesulfonylimide (LiTFSI); the solvent is 1,3-dioxolane and ethylene dioxane A mixture of alcohol dimethyl ether (DOL/DME) in a volume ratio of 1:1; the solute concentration is 1 M. The battery structure is lithium metal/carbon paper/diaphragm/carbon paper/lithium metal.

Accompanying drawing 1 is the cycle curve of the battery at a current density of 0.5 mA/cm ² . The lithium metal deposition/dissolution capacity in this battery was 1 mAh/cm ² . Combined with Figure 1, the metal lithium deposition/dissolution overpotential of the metal lithium symmetric battery prepared by this method is 20 mV, and the metal lithium negative electrode can stably and continuously deposit/dissolve for 800 cycles, thus proving that carbon paper can be used as an additive layer. It suppresses the short-circuit problem of the battery caused by the free growth of lithium dendrites piercing the separator, and effectively protects the metal lithium negative electrode during the cycle.

Example 2 Metal Lithium Symmetrical Battery Protected by Carbon Paper at High Current Density in Ether Electrolyte System

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is ether electrolyte, the solute is lithium bistrifluoromethanesulfonylimide (LiTFSI); the solvent is 1,3-dioxolane and ethylene dioxane A mixture of alcohol dimethyl ether (DOL/DME) in a volume ratio of 1:1; the solute concentration is 1 M. The battery structure is lithium metal/carbon paper/diaphragm/carbon paper/lithium metal.

Accompanying drawing 2 is the cycle curve of the battery at a current density of 5 mA/cm ² . The lithium metal deposition/dissolution capacity in this battery was 1 mAh/cm ² . Combined with Figure 2, the metal lithium deposition/dissolution overpotential of the metal lithium symmetric battery prepared by this method is about 200 mV, and the metal lithium negative electrode can stably and continuously deposit/dissolve for 4000 cycles. The layer can not only effectively inhibit the battery short-circuit problem caused by the free growth of lithium dendrites piercing the separator under low current conditions, and realize the protection of the negative electrode, but also has excellent metal lithium negative electrode protection ability under the condition of high current density.

Example 3 Metal Lithium Symmetrical Battery Protected by Carbon Paper in Carbonate Electrolyte System

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is an ester electrolyte, the solute is lithium hexafluorophosphate (LiPF ₆ ); the solvent is ethylene carbonate and diethyl carbonate (EC/DEC) at a volume ratio of 1:1 mixed solution; the solute concentration is 1 M. The battery structure is lithium metal/carbon paper/diaphragm/carbon paper/lithium metal.

Accompanying drawing 3 is the cycle curve of the battery at a current density of 0.5 mA/cm ² . The lithium metal deposition/dissolution capacity in this battery was 1 mAh/cm ² . Combined with Figure 3, the metal lithium deposition/dissolution overpotential of the metal lithium symmetric battery prepared by this method is 15 mV, and the metal lithium negative electrode can stably and continuously deposit/dissolve for 120 cycles. In combination with Example 1, it is proved that carbon paper is used as an added layer Not only can it effectively suppress the battery short circuit problem caused by the free growth of lithium dendrites piercing the separator in the ether electrolyte system, and realize the protection of the negative electrode, it can also realize the protection of metal lithium in the carbonate electrolyte system.

Example 4 Metal lithium symmetric battery protected by metal aluminum mesh

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is an ester electrolyte, the solute is lithium hexafluorophosphate (LiPF ₆ ); the solvent is ethylene carbonate and diethyl carbonate (EC/DEC) at a volume ratio of 1:1 mixed solution; the solute concentration is 1 M. The battery structure is metal lithium/metal aluminum mesh/diaphragm/metal aluminum mesh/metal lithium.

Accompanying drawing 4 is the cycle curve of the battery at a current density of 1 mA/cm ² . The lithium metal deposition/dissolution capacity in this battery was 1 mAh/cm ² . Combined with Figure 4, the metal lithium deposition/dissolution overpotential of the metal lithium symmetric battery prepared by this method is between 100-600 mV, and the overpotential increases slowly with the increase of the number of cycles, and the metal lithium negative electrode can stably continue the deposition/dissolution cycle 200 cycles, combined with Example 1, it is proved that replacing the metal aluminum mesh as an additional layer can also effectively inhibit the short circuit problem of the battery caused by the free growth of lithium dendrites piercing the separator, and realize the protection of the negative electrode.

Example 5 Metal sodium symmetric battery protected by carbon paper at low current density in ether electrolyte system

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is ether electrolyte, the solute is sodium trifluoromethanesulfonate (NaSO ₃ CF ₃ ); the solvent is diethylene glycol dimethyl ether (DGME); the solute is The concentration is 1M. The battery structure is sodium metal/carbon paper/diaphragm/carbon paper/sodium metal.

Figure 5 is the cycle curve of the battery at a current density of 0.5 mA/cm ² . The deposition/dissolution capacity of metallic sodium in this battery was 1 mAh/cm ² . Combined with Figure 5, the metal sodium deposition/dissolution overpotential of the metal sodium symmetric battery prepared by this method is 20 mV, and the metal sodium negative electrode can stably and continuously deposit/dissolve for 260 cycles, thus proving that carbon paper is used as an added layer in the cycle process. Effectively protect the metal sodium anode.

Example 6 Metal sodium symmetric battery protected by carbon paper at high current density in ether electrolyte system

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is ether electrolyte, the solute is sodium trifluoromethanesulfonate (NaSO ₃ CF ₃ ); the solvent is diethylene glycol dimethyl ether (DGME); the solute is The concentration is 1M. The battery structure is sodium metal/carbon paper/diaphragm/carbon paper/sodium metal.

Accompanying drawing 6 is the cycle curve of the battery at a current density of 5 mA/cm ² . The deposition/dissolution capacity of metallic sodium in this battery was 1 mAh/cm ² . Combined with Figure 6, the metal sodium deposition/dissolution overpotential of the metal sodium symmetric battery prepared by this method is 50-100 mV, and the metal sodium negative electrode can stably and continuously deposit/dissolve for 1200 cycles. In combination with Example 5, it is proved that carbon paper is used as The added layer can not only effectively protect the metal sodium anode under the condition of small current, but also has excellent protection ability of the metal sodium anode under the condition of high current density.

Example 7 Metal Potassium Symmetrical Battery Protected by Carbon Paper

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is ether electrolyte, the solute is potassium hexafluorophosphate (KPF6); the solvent is ethylene carbonate and diethyl carbonate (EC/DEC) according to the volume ratio of 1 :1 mixed solution; solute concentration is 1 M. The battery structure is potassium metal/carbon paper/diaphragm/carbon paper/potassium metal.

Accompanying drawing 7 is the cycle curve of the battery at a current density of 0.5 mA/cm ² . The lithium metal deposition/dissolution capacity in this battery was 1 mAh/cm ² . Combined with Fig. 7, metal lithium deposition/dissolution overpotential of metal potassium symmetric battery prepared by this method is about 20 mV, and metal potassium negative electrode can stably and continuously deposit/dissolve for 300 cycles, thus proving that carbon paper can also be used as an additive layer. Can effectively protect metal potassium anode.

Comparative example 1 Metal lithium symmetric battery without any protection

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is ether electrolyte, the solute is lithium bistrifluoromethanesulfonylimide (LiTFSI); the solvent is 1,3-dioxolane and ethylene dioxane A mixture of alcohol dimethyl ether (DOL/DME) in a volume ratio of 1:1; the solute concentration is 1 M. The battery structure is lithium metal/diaphragm/lithium metal.

Figure 8 is the cycle curve of the battery at a current density of 0.5 mA/cm ² . The lithium metal deposition/dissolution capacity in this battery was 1 mAh/cm ² . Combined with Figure 8, the metal lithium deposition/dissolution overpotential of the metal lithium symmetric battery without any protection is about 15 mV at first, and then the overpotential increases rapidly with the cycle. Stablize.

Comparative example 2 Metal sodium symmetric battery without any protection

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is ether electrolyte, the solute is sodium trifluoromethanesulfonate (NaSO ₃ CF ₃ ); the solvent is diethylene glycol dimethyl ether (DGME); the solute is The concentration is 1M. The battery structure is sodium metal/diaphragm/sodium metal.

Accompanying drawing 9 is the cycle curve of the battery at a current density of 0.5 mA/cm ² . The lithium metal deposition/dissolution capacity in this battery was 1 mAh/cm ² . Combined with Figure 9, the sodium metal in the sodium metal symmetric battery without any protection can hardly complete the deposition/dissolution cycle, the overpotential is extremely large, and the negative electrode is extremely unstable.

Comparative Example 3 Metal Potassium Symmetrical Battery Without Any Protection

Symmetrical battery assembly: the battery model is CR2032, the diaphragm is made of PP, the electrolyte is ether electrolyte, the solute is potassium hexafluorophosphate (KPF ₆ ); the solvent is ethylene carbonate and diethyl carbonate (EC/DEC) by volume ratio 1:1 mixture; solute concentration is 1 M. The battery structure is sodium metal/diaphragm/sodium metal.

Figure 10 is the cycle curve of the battery at a current density of 0.5 mA/cm ² . The lithium metal deposition/dissolution capacity in this battery was 1 mAh/cm ² . Combined with Figure 10, the metal potassium in the metal potassium symmetric battery without any protection can only complete 20 deposition/dissolution cycles, and the overpotential is extremely large, and the negative electrode is unstable.

Therefore, the present invention provides a simple and effective protection method for lithium metal negative electrodes, and the same method can be transplanted to the protection of negative electrodes for sodium metal batteries and potassium metal batteries. Even without changing the traditional manufacturing process of the alkali metal, the cycle life of the alkali metal negative electrode can be significantly improved, and the overpotential of the negative electrode of the battery can be reduced. It has extremely high practical value.

Claims (10)

1. A protection method for the metal negative pole of an alkali metal secondary battery, characterized in that: the protection method for the metal negative pole of the alkali metal secondary battery is to set an additional layer on the surface of the metal negative pole of the alkali metal secondary battery to realize the alkali metal secondary battery Protection of the metal negative electrode. 2. The method for protecting the metal negative electrode of the alkali metal secondary battery according to claim 1, wherein the structure of the added layer is a film structure or a thin mesh structure. 3. The method for protecting the metal negative electrode of the alkali metal secondary battery according to claim 1, wherein the material of the added layer includes one or more of carbon materials, metals, compounds, and conductive polymers. 4. according to the protection method of the metal negative electrode of alkali metal secondary battery described in claim 3, it is characterized in that, described metal comprises aluminum, iron, cobalt, nickel, copper, zinc, stainless steel; Described carbon material comprises carbon fiber, carbon tube , Graphene; the compound includes one or more of oxides, sulfides, nitrides, phosphides, carbides, and borides. 5. according to the protection method of the metal negative electrode of alkali metal secondary battery described in claim 4, it is characterized in that, described carbon material comprises carbon paper, carbon cloth, 3D graphene; Described metal comprises metallic nickel mesh, metallic aluminum mesh, Stainless steel mesh, metal copper mesh, nickel foam, copper foam. 6. The protection method of the metal negative electrode of the alkali metal secondary battery according to claim 3, wherein the material of the added layer is a single carbon material, metal or conductive polymer; or the material of the added layer is carbon Composites of materials and compounds. 7. The method for protecting the metal negative electrode of the alkali metal secondary battery according to claim 1, wherein the alkali metal comprises lithium, sodium or potassium. 8. An alkali metal secondary battery, comprising a positive pole and a metal negative pole; it is characterized in that, the surface of the metal negative pole is provided with an added layer; the structure of the added layer is a film structure or a thin net structure; the material of the added layer Including one or more of carbon materials, metals, compounds, and conductive polymers; the metals include, aluminum, stainless steel, and copper; the carbon materials include carbon fibers, carbon tubes, and graphene; the compounds include oxides, One or more of sulfide, nitride, phosphide, carbide, boride. 9. The alkali metal secondary battery according to claim 8, wherein the added layer is carbon paper, carbon cloth, 3D graphene, metal nickel mesh, metal aluminum mesh, stainless steel mesh, metal copper mesh, high conductivity molecular film; or the added layer is a composite material formed of carbon tubes or graphene, transition metal sulfides, and transition metal oxides. 10. The application of the added layer in protecting the metal negative electrode of the alkali metal secondary battery or in the preparation of the alkali metal secondary battery, characterized in that, the structure of the added layer is a film structure or a thin net structure; the material of the added layer includes One or more of carbon materials, metals, compounds, and conductive polymers; the metals include, aluminum, stainless steel, and copper; the carbon materials include carbon fibers, carbon tubes, and graphene; the compounds include oxides, sulfurized One or more of compounds, nitrides, phosphides, carbides, borides.