Carbon lithium composites via intercalation and paused dissolution and electrochemical cells comprising the same

Abstract

In one aspect, the disclosure relates to In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to compounds carbon-lithium composite materials, methods of making the same, and electrochemical cells comprising the same. In one aspect, the carbon-lithium composite materials can be made, in part, from agricultural waste. In another aspect, the disclosed electrochemical cells have a high energy density and good thermal and chemical stability over multiple charge cycles.

Description

CARBON LITHIUM COMPOSITES VIA INTERCALATION AND PAUSED DISSOLUTION AND ELECTROCHEMICAL CELLS COMPRISING THE SAMECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 63 / 656,800, filed June 6, 2024, which is incorporated herein by reference in its entirety.BACKGROUND

[0002] Lithium-ion batteries have been widely used as an energy source for a variety of portable electronic systems due to their energy density and rechargeability. The current design of many lithium-ion batteries includes a metal-oxide-based cathode comprising high-value metals, such as nickel, cobalt, and manganese. Graphitic carbon-lithium composites have been investigated to replace the metal-oxide based cathode in lithium-ion batteries to address the high cost and material scarcity associated with high-value metals. Current techniques to produce carbon-lithium composites include electrodeposition, thermal infiltration, and mechanical rolling.

[0003] Electrodeposition utilizes a separate electrochemical deposition cell and deposits lithium metal into a hosting material, such as a porous, conductive carbon base. Electrodeposition has some advantages, such as the ability to use different types of flexible carbon bases, and the ability to directly deposit lithium onto the carbon. However, critical shortcomings, including a complicated electrodeposition system preparation, an uncontrollable deposition process, and a low theoretical lithium content ceiling, make it a suboptimal pathway for the production of carbon lithium composites.

[0004] Thermal infiltration involves coating Si-coated carbon bases with molten lithium in anaerobic environments. This process allows lithium to infiltrate the carbon base rapidly, leading to a uniform deposition of lithium. Although thermal infiltration is simpler than electrodeposition, this process has strict limitations on the types of base material used and has thermostability issues, proving yet another flawed pathway for the mass application of carbon lithium composites.

[0005] Mechanical rolling processes synthesize carbon-lithium composites by mechanically rolling layers of 2-dimensional carbon materials (for example, MXenes) and lithium foils together. In the process, lithium can be stored between the carbon layers, endowing the new material with promising properties. However, the process is underdeveloped, and the properties of carbon lithium composites produced by this method are not well-understood.

[0006] In view of the foregoing challenges, there exists a need for a method to fabricate carbon-lithium composite materials that demonstrate a high energy density, good thermal and chemical stability, and remains cost-efficient. These needs and other needs are satisfied by the present disclosure.SUMMARY

[0007] In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to compounds carbon-lithium composite materials, methods of making the same, and electrochemical cells comprising the same. In one aspect, the carbon-lithium composite materials can be made, in part, from agricultural waste. In another aspect, the disclosed electrochemical cells have a high energy density and good thermal and chemical stability over multiple charge cycles.

[0008] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. In addition, all optional and preferred features and modifications of the described embodiments are usable in all aspects of the disclosure taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0010] FIG. 1 is a schematic of a proposed mechanism for the synthesis of the disclosed carbon-lithium composites.

[0011] FIGs. 2A-2D show formation of a high surface area carbon-lithium material produced by pyrolysis of the silanized cellulosic-lithium material. (FIG. 2A) The pyrolysis process drives inside-out flame propagation, resulting in the formation of graphitic carbon sandwiching lithium. (FIG. 2B) SEM image of the carbon-lithium material. The lithium could be observed on the inside of the material. (FIG. 2C) XRD of the carbon-lithium material. (FIG. 2D)Discharge voltage / current testing results of the carbon-lithium material in an electrochemical cell.

[0012] FIG. 3 shows discharge-recharge testing result for an electrochemical cell comprising a carbon-lithium material produced by pyrolysis of the cellulosic-lithium material with an ionic liquid additive.

[0013] FIG. 4 shows a testing setup for an electrochemical cell comprising a carbon-lithium material.

[0014] FIG. 5 shows a schematic of a method for producing a lithium graphitic carbon complex starting from cellulose fiber.

[0015] Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or can be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.DETAILED DESCRIPTION

[0016] Disclosed herein is a method to fabricate carbon-lithium composite materials that demonstrate a high energy density, good thermal and chemical stability, and remains costefficient. Also disclosed are electrochemical cells including the composite materials, small appliances using the electrochemical cells, and methods for short-term energy storage making use of the electrochemical cells.Electrochemical Cell

[0017] In one aspect, disclosed herein is an electrochemical cell including at least a first electrode including a carbon-lithium composite material; a second electrode; a compartment, wherein the compartment houses the first electrode and the second electrodes; and a network of lithium infused carbon tubes in contact with the first electrode and the second electrode, wherein the compartment contains the lithium infused carbon tubes. In some aspects, the electrochemical cell further includes a fluid in contact with the first electrode and the second electrode, wherein the fluid can be a liquid or a gas. In still another aspect, lithium in the lithium infused carbon tubes migrates from a first wall of the lithium infused carbon tubes towards a second wall of the lithium infused carbon tubes under influence of an applied field and undergoes a change in oxidation state from Li(0) to Li (I).

[0018] In one aspect, the lithium in the carbon-lithium composite material is intercalated into the carbon-lithium composite material. In another aspect, the second electrode can be or include carbon black, mesoporous carbon, graphitic carbon, another electrically conductive material, or any combination thereof.

[0019] In one aspect, a voltage of the electrochemical cell can be from about 0.5 V to about 10.8 V, or from about 0.75 V to about 10.5 V, or can be about 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or about 10.8 V, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In another aspect, a cycle life of the electrochemical cell is from about 2 cycles to about 10 cycles, from about 5 cycles to about 10 cycles, or can be about 2, 3, 4, 5, 6, 7, 8, 9, or about 10 cycles. In still another aspect, a cycle time of the electrochemical cell is from about 5 h to about 30 h, or from about 5 h to about 20 h, or can be about 5, 10, 15, 20, 25, or about 30 h, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values..

[0020] In any of these aspects, in the electrochemical cell, the carbon-lithium composite material can have a specific surface area of from about 20 m2 / g to about 1060 m2 / g, or from about 40 m2 / g to about 160 m2 / g, or about 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 250, 500, 750, 1000, or about 1060 m2 / g, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values.

[0021] In one aspect, in the electrochemical cell, the carbon-lithium composite material includes a plurality of repeating structures. In another aspect, the plurality of repeating structures are spaced from about 0.5 nm apart to about 2 nm apart, or from about 0.5 nm to about 1 nm apart, or at about 0.5 nm, 0.75 nm, 1 nm, 1.25 nm, 1.5 nm, 1.75 nm, or about 2 nm apart, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In one aspect, the plurality of repeating structures form an electrically- conductive network. In one aspect, the electrochemical cell has a circular, triangular, or rectangular geometric shape having at least one face, wherein the first electrode and the second electrode are on the same at least one face of the geometric shape.Small Appliance

[0022] Also disclosed herein is a small appliance including the disclosed electrochemical cell. In an aspect, the electrochemical cell is removable from the small appliance. In another aspect, the small appliance can be a smartphone, smart watch, laptop computer, tablet computer, electronic toy, an interactive display, or any combination thereof.Method for Energy Storage

[0023] In another aspect, disclosed herein is a method for short-term energy storage, the method including charging the disclosed electrochemical cell. Further in this aspect, charging the electrochemical cell is accomplished using a solar generator, a wind generator, or both a solar generator and a wind generator.Method for Producing a Carbon-Lithium Composite Material

[0024] In one aspect, disclosed herein is a method for producing a carbon-lithium composite material, the method including at least the following steps:(a) soaking a cellulosic material in a lithium salt solution to produce a cellulosic-lithium material;(b) drying the cellulosic-lithium material to produce a dried cellulosic-lithium material; and(c) pyrolyzing the dried cellulosic-lithium material to produce a carbon-lithium composite material.

[0025] In a further aspect, cellulosic material can be or include cellulose, hemicellulose, lignin, or any combination thereof. In another aspect, the cellulosic material can be sourced from a plant or agricultural residue such as, for example, cotton, a hardwood, a softwood, sawdust, flax, hemp, sisal, lyocell, bamboo, corn, another grain, sugarcane bagasse, or any combination thereof.

[0026] In one aspect, the lithium salt solution can be an aqueous solution, wherein the lithium salt solution can be selected from a lithium halide such as, for example, lithium chloride,, a lithium carboxylate such as, for example, lithium acetate, lithium nitrate, lithium carbonate, or any combination thereof. In one non-limiting aspect, the lithium salt can be lithium chloride, the cellulosic material can be cellulose, and the lithium salt solution can be an aqueous solution.

[0027] In any of these aspects, the method can further include performing surface modification such as, for example, silanization, on the cellulosic-lithium material after step (a). In one aspect, silanization can be conducted via chemical vapor deposition of a silane onto the cellulosic-lithium material. In another aspect, the silane can be a trichloro(alkyl)silane such as, for example, trichloro(octyl)silane, or another trichloro(alkyl)silane having from about 1 to about 12 carbon atoms in a hydrocarbon fragment, or about 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , or about 12 carbon atoms.

[0028] In another aspect, the lithium salt solution can further include an additive. In a further aspect, the additive can be present in an amount of from about 1 :3 to about 1 :20 relative toan amount of cellulose, or of about 1 :3, 1 :4, 1 :5, 1 :6, 1 :7, 1 :8, 1 :9, 1 :10, 1 :11 , 1 :12, 1 :13, 1 :14, 1 :15, 1 :16, 1 :17, 1 :18, 1 :19, or about 1 :20 relative to the amount of cellulose. In a further aspect, the additive can be dimethylacetamide (DMAc), an ionic liquid, or any combination thereof. In an aspect, the ionic liquid can be 1-allyl-3-methylimidazolium chloride (AMIMCI), 1-ethyl-3-methylimidazolium acetate (EM IM Ac), or any combination thereof. In another aspect, when the additive is present, the lithium salt solution exhibits viscoelastic behavior.

[0029] In one aspect, in the disclosed method step (b) is carried out at from about 80 °C to about 150 °C, or at about 80, 85, 90, 95, 100, 110, 120, 130, 140, or about 150 °C. In another aspect, step (c) Is carried out at from about 300 °C to about 1500 °C, or at from about 400 °C to about 1000 °C, or at about 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, or about 1500 °C, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values.

[0030] Also disclosed herein is a carbon-lithium composite material made by the disclosed method. In another aspect, the carbon-lithium composite material can have a specific surface area of from about 20 m2 / g to about 1060 m2 / g, or from about 40 m2 / g to about 160 m2 / g, or about 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 250, 500, 750, 1000, or about 1060 m2 / g, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values.

[0031] In one aspect, the carbon-lithium composite material includes a plurality of repeating structures. In another aspect, the plurality of repeating structures are spaced from about 0.5 nm apart to about 2 nm apart, or from about 0.5 nm to about 1 nm apart, or at about 0.5 nm, 0.75 nm, 1 nm, 1.25 nm, 1.5 nm, 1 .75 nm, or about 2 nm apart, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In one aspect, the plurality of repeating structures form an electrically-conductive network.

[0032] Many modifications and other embodiments disclosed herein will come to mind to one skilled in the art to which the disclosed compositions and methods pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosures are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. The skilled artisan will recognize many variants and adaptations of the aspects described herein. These variants and adaptations are intended to be included in the teachings of this disclosure and to be encompassed by the claims herein.

[0033] Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0034] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure.

[0035] Any recited method can be carried out in the order of events recited or in any other order that is logically possible. That is, unless otherwise expressly stated, it is in no way intended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not specifically state in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to arrangement of steps or operational flow, plain meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the specification.

[0036] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided herein can be different from the actual publication dates, which can require independent confirmation.

[0037] While aspects of the present disclosure can be described and claimed in a particular statutory class, such as the system statutory class, this is for convenience only and one of skill in the art will understand that each aspect of the present disclosure can be described and claimed in any statutory class.

[0038] It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed compositions and methods belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0039] Prior to describing the various aspects of the present disclosure, the following definitions are provided and should be used unless otherwise indicated. Additional terms may be defined elsewhere in the present disclosure.Definitions

[0040] As used herein, “comprising” is to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to, but does not preclude the presence or addition of one or more features, integers, steps, or components, or groups thereof. Moreover, each of the terms “by”, “comprising,” “comprises”, “comprised of,” “including,” “includes,” “included,” “involving,” “involves,” “involved,” and “such as” are used in their open, non-limiting sense and may be used interchangeably. Further, the term “comprising” is intended to include examples and aspects encompassed by the terms “consisting essentially of” and “consisting of.” Similarly, the term “consisting essentially of” is intended to include examples encompassed by the term “consisting of.”

[0041] As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a lithium salt,” “a cellulosic material,” or “an ionic liquid,” include, but are not limited to, mixtures or combinations of two or more such lithium salts, cellulosic materials, or ionic liquids, and the like.

[0042] It should be noted that ratios, concentrations, amounts, and other numerical data can be expressed herein in a range format. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms a further aspect. For example, if the value “about 10” is disclosed, then “10” is also disclosed.

[0043] When a range is expressed, a further aspect includes from the one particular value and / or to the other particular value. For example, where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure, e.g. the phrase “x to y” includes the range from ‘x’ to ‘y’ as well as the range greater than ‘x’ and less than ‘y’. The range can also be expressed as an upper limit, e.g. ‘about x, y, z, or less’ and should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and‘about z’ as well as the ranges of ‘less than x’, less than y’, and ‘less than z’. Likewise, the phrase ‘about x, y, z, or greater’ should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z’ as well as the ranges of ‘greater than x’, greater than y’, and ‘greater than z’. In addition, the phrase “about ‘x’ to ‘y’”, where ‘x’ and ‘y’ are numerical values, includes “about ‘x’ to about ‘y’”.

[0044] It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a numerical range of “about 0.1% to 5%” should be interpreted to include not only the explicitly recited values of about 0.1% to about 5%, but also include individual values (e.g., about 1 %, about 2%, about 3%, and about 4%) and the sub-ranges (e.g., about 0.5% to about 1.1%; about 5% to about 2.4%; about 0.5% to about 3.2%, and about 0.5% to about 4.4%, and other possible sub-ranges) within the indicated range.

[0045] As used herein, the terms “about,” “approximate,” “at or about,” and “substantially” mean that the amount or value in question can be the exact value or a value that provides equivalent results or effects as recited in the claims or taught herein. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art such that equivalent results or effects are obtained. In some circumstances, the value that provides equivalent results or effects cannot be reasonably determined. In such cases, it is generally understood, as used herein, that “about” and “at or about” mean the nominal value indicated ±10% variation unless otherwise indicated or inferred. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about,” “approximate,” or “at or about” whether or not expressly stated to be such. It is understood that where “about,” “approximate,” or “at or about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0046] As used herein, the terms “optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0047] Unless otherwise specified, temperatures referred to herein are based on atmospheric pressure (i.e. one atmosphere) but can be executed at any thermodynamically feasible conditions.

[0048] Now having described the aspects of the present disclosure, in general, the following Examples describe some additional aspects of the present disclosure. While aspects of the present disclosure are described in connection with the following examples and the corresponding text and figures, there is no intent to limit aspects of the present disclosure to this description. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of the present disclosure.ASPECTS

[0049] The present disclosure can be described in accordance with the following numbered aspects, which should not be confused with the claims.

[0050] Aspect 1. An electrochemical cell comprising a first electrode comprising a carbonlithium composite material; a second electrode; a compartment, wherein the compartment houses the first electrode and the second electrodes; and a network of lithium infused carbon tubes in contact with the first electrode and the second electrode, wherein the compartment contains the lithium infused carbon tubes.

[0051] Aspect 2. The electrochemical cell of aspect 1, further comprising a fluid in contact with the first electrode and the second electrode.

[0052] Aspect 3. The electrochemical cell of aspect 2, wherein the fluid comprises a liquid or a gas.

[0053] Aspect 4. The electrochemical cell of any one of aspects 1-3, wherein lithium in the lithium infused carbon tubes migrates from a first wall of the lithium infused carbon tubes towards a second wall of the lithium infused carbon tubes under influence of an applied field, and wherein the lithium undergoes a change in oxidation state from Li(0) to Li (I).

[0054] Aspect 5. The electrochemical cell of any one of aspects 1-4, wherein lithium in the carbon-lithium composite material is intercalated into the carbon-lithium composite material.

[0055] Aspect 6. The electrochemical cell of any one of aspects 1-5, wherein the second electrode comprises carbon black, mesoporous carbon, graphitic carbon, another electrically conductive material, or any combination thereof.

[0056] Aspect 7. The electrochemical cell of any one of aspects 1-6, wherein a voltage of the electrochemical cell is from about 0.5 V to about 10.8 V.

[0057] Aspect 8. The electrochemical cell of any one of aspects 1-7, wherein a cycle life of the electrochemical cell is from about 2 cycles to about 10 cycles.

[0058] Aspect 9. The electrochemical cell of any one of aspects 1-8, wherein a cycle time of the electrochemical cell is from about 5 h to about 30 h.

[0059] Aspect 10. The electrochemical cell of any one of aspects 1-9, wherein the carbonlithium composite material has a specific surface area of from about 20 m2 / g to about 1060 m2 / g.

[0060] Aspect 11. The electrochemical cell of any one of aspects 1-10, wherein the carbonlithium composite material comprises a plurality of repeating structures.

[0061] Aspect 12. The electrochemical cell of aspect 11 , wherein the plurality of repeating structures are spaced from about 0.5 nm apart to about 2 nm apart.

[0062] Aspect 13. The electrochemical cell of aspect 11 or 12, wherein the plurality of repeating structures form an electrically-conductive network.

[0063] Aspect 14. The electrochemical cell of any one of aspects 1-13, wherein the electrochemical cell comprises a circular, triangular, or rectangular geometric shape having at least one face, wherein the first electrode and the second electrode are on the same at least one face of the geometric shape.

[0064] Aspect 15. A small appliance comprising the electrochemical cell of any one of aspects 1-14.

[0065] Aspect 16. The small appliance of aspect 15, wherein the electrochemical cell is removable from the small appliance.

[0066] Aspect 17. The small appliance of aspect 15 or 16, wherein the small appliance comprises a smartphone, smart watch, laptop computer, tablet computer, electronic toy, an interactive display, or any combination thereof.

[0067] Aspect 18. A method for short-term energy storage, the method comprising charging the electrochemical cell of any one of aspects 1-14.

[0068] Aspect 19. The method of aspect 18, wherein charging the electrochemical cell is accomplished using a solar generator, a wind generator, or both a solar generator and a wind generator.

[0069] Aspect 20. A method for producing a carbon-lithium composite material, the method comprising:(a) soaking a cellulosic material in a lithium salt solution to produce a cellulosic-lithium material;(b) drying the cellulosic-lithium material to produce a dried cellulosic-lithium material; and(c) pyrolyzing the dried cellulosic-lithium material to produce a carbon-lithium composite material.

[0070] Aspect 21. The method of aspect 20, wherein the cellulosic material comprises cellulose, hemicellulose, lignin, or any combination thereof.

[0071] Aspect 22. The method of aspect 20 or 21, wherein the cellulosic material is sourced from a plant or agricultural residue.

[0072] Aspect 23. The method of aspect 22, wherein the plant or agricultural residue comprises cotton, a hardwood, a softwood, sawdust, flax, hemp, sisal, lyocell, bamboo, corn, another grain, sugarcane bagasse, or any combination thereof.

[0073] Aspect 24. The method of any one of aspects 20-23, wherein the lithium salt solution comprises an aqueous solution.

[0074] Aspect 25. The method of any one of aspects 20-24, wherein the lithium salt solution comprises a lithium halide, a lithium carboxylate, lithium nitrate, lithium carbonate, or any combination thereof.

[0075] Aspect 26. The method of any one of aspects 20-25, wherein the lithium salt comprises lithium chloride, the cellulosic material comprises cellulose, and the lithium salt solution comprises an aqueous solution.

[0076] Aspect 27. The method of any one of aspects 20-26, further comprising performing surface modification on the cellulosic-lithium material after step (a).

[0077] Aspect 28. The method of aspect 27, wherein surface modification comprises silanization.

[0078] Aspect 29. The method of aspect 28, wherein silanization is conducted via chemical vapor deposition of a silane onto the cellulosic-lithium material.

[0079] Aspect 30. The method of aspect 29, wherein the silane comprises a trichloro(alkyl)silane.

[0080] Aspect 31. The method of aspect 30, wherein a hydrocarbon fragment of the trichloro(alkyl)silane comprises from about 1 to about 12 carbon atoms.

[0081] Aspect 32. The method of any one of aspects 20-31, wherein the lithium salt solution further comprises an additive.

[0082] Aspect 33. The method of aspect 32, wherein the additive is present in an amount of from about 1 :3 to about 1 :20 relative to an amount of cellulose.

[0083] Aspect 34. The method of aspect 32 or 33, wherein the additive comprises dimethylacetamide (DMAc), an ionic liquid, or any combination thereof.

[0084] Aspect 35. The method of aspect 34, wherein the ionic liquid comprises 1-allyl-3- methylimidazolium chloride (AM I MCI), 1-ethyl-3-methylimidazolium acetate (EMIMAc), or any combination thereof.

[0085] Aspect 36. The method of any one of aspects 20-35, wherein step (b) is carried out at from about 80 °C to about 150 °C.

[0086] Aspect 37. The method of any one of aspects 20-36, wherein step (c) Is carried out at from about 300 °C to about 1500 °C.

[0087] Aspect 38. A carbon-lithium composite material made by the method of any one of aspects 20-37.

[0088] Aspect 39. The carbon-lithium composite material of aspect 38, wherein the carbonlithium composite material has a specific surface area of from about 20 m2 / g to about 1060 m2 / g.

[0089] Aspect 40. The carbon-lithium composite material of aspect 38 or 39, wherein the carbon-lithium composite material comprises a plurality of repeating structures.

[0090] Aspect 41. The carbon-lithium composite material of aspect 40, wherein the plurality of repeating structures are spaced from about 0.5 nm apart to about 2 nm apart.

[0091] Aspect 42. The carbon-lithium composite material of aspect 40 or 41 , wherein the plurality of repeating structures form an electrically-conductive network.EXAMPLES

[0092] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices and / or methods claimed herein are made and evaluated, and are intended to be purely exemplary of the disclosure and are not intended to limit the scope of what the inventors regard as their disclosure. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric.Example 1 : Materials and MethodsPreparation of Cellulose-LiCI Sample

[0093] Cellulose samples were mixed with 80 °C water and stirred for 5 minutes. Lithium chloride was then added to the mixture. The weight of lithium chloride was 60% of the cellulose. The mixture was then dried in an oven with a temperature set at 120 °C for 6 hours.Preparation of Cellulose-LiCI-DMAc Sample

[0094] DMAc and cellulose equal to 8% of the weight of DMAc (g / g) were combined and stirred for 15 minutes. The mixture was then heated up to 150 °C and kept at this temperature while stirring for another 15 minutes. Lithium chloride equal to 8% of DMAc was then added to the mixture and stirred for an additional 12 hours while cooling down to room temperature.Preparation of Cellulose-LiCI-IL Sample

[0095] Pre-dried lithium chloride was added to pre-dried ionic liquid and the mixture was heated while stirred to 80 °C for 3 hours. Cellulose equal to 5% of the mixture (g / g) was then added into the mixture and further stirred for 1 hour.Preparation of Silanized Cellulose-LiCI Sample

[0096] A dried LiCI-cellulose sample was placed in a vacuum desiccator and 100 pL of trichloro(octyl)silane was added in a small vial and placed in the desiccator. The desiccator was then evacuated for 2 minutes and put in an oven with a temperature of 90 °C for 1 hour.Pyrolysis to Form Carbon-Lithium Material

[0097] The prepared cellulose samples (Cellulose-LiCI, Cellulose-LiCI-DMAc, Cellulose- LiCI- IL, silanized Cellulose-LiCI) were put into a crucible and heat treated in a muffle furnace at a set point of 600 °C, dwell time of 1 hour, and heating rate of 40 °C / min.Preparation of a Battery Cell

[0098] As indicated in FIG. 4, 60 mg of carbon-lithium material was loaded in a Teflon nut as the anode material along with 30 mg of carbon black on the opposite side as the cathode material. 200 pL of 1M LiCI aqueous solution was added as the electrolyte. Two bolts were screwed onto the Teflon nut at the two electrodes.Example 2: Results

[0099] Lithium salts used in exemplary experiments included lithium chloride, lithium acetate, lithium nitrate, lithium carbonate, and combinations thereof. Cellulosic materials used included plant materials where the primary components included cellulose, hemicellulose, and / or lignin such as, for example, cotton, wood including hardwoods and softwoods, sawdust, and agricultural residue including flax, hemp, bamboo, corn, grain, and sugarcane bagasse.

[0100] In many experiments, the lithium salt was lithium chloride, the cellulosic material was cellulose, and these were combined in an aqueous solution. In some experiments, the aqueous solution also included an additive such as, for example, DMA or an ionic liquid. Suitable ionic liquids included, but were not limited to, 1-allyl-3-methylimidazolium chloride (AMIMCI), 1-ethyl-3-methylimidazolium acetate (EMIMAc), and combinations thereof. The ratio of the additive to cellulose was typically between 1 :3 and 1 :10. In some experiments, cellulosic material and DMAc were combined first, followed by the addition of a lithium-salt. In other experiments, lithium-salt and the ionic liquid were combined first, followed by the addition of cellulosic material. The cellulosic-lithium material with an additive was dried between 80 and 100° C. In experiments where the aqueous solution contained an additive, the solutions exhibited viscoelastic behavior.

[0101] In some experiments, the cellulosic-lithium material was silanized by chemical vapor deposition of trichloro(octyl)silane, forming a flame-resistant coating, which forced the combustion of the cellulosic material to start from inside the cellulose fibers. This further enabled charge exchange between the embedded lithium and the electrolyte solution and increased the specific surface area to maximize ion exchange.

[0102] In some experiments, the cellulosic-lithium material, with or without the additive, and with or without silanization, was pyrolyzed. During pyrolysis, the material was heated to between 400 °C and 1500 °C. The specific surface area of the carbon-lithium material was between 40 m2 / g and 160 m2 / g. During heating the cellulose in the material transformed into graphitic carbon, the lithium-salt dissociated, and lithium was embedded within the newly produced carbon-lithium material, FIG. 2A.

[0103] After pyrolysis, lithium was observed on both the inside and the outside of the graphitic carbon structures (FIG. 2B) highlighting that the lithium infusion process was successful. An X-ray crystallography analysis revealed that the carbon-lithium material contained a series of repeating structures, as highlighted in FIG. 2C. The spacing between the repeating structures was calculated to be approximately 0.75 nm, close to the distance between graphene oxide layers. Similar results are expected if the spacing between the repeating structures ranges from 0.5 nm to 2 nm. The repeating structures were graphene oxide multi-layer structures with lithium trapped in between. In some experiments, the carbon-lithium material included lithium intercalated within the carbon-lithium material, typically in a random distribution.

[0104] The carbon-lithium material was used as an electrode for an electrochemical cell. An exemplary electrochemical cell included a first electrode, a second electrode, and a compartment containing the first and second electrodes. The first electrode material was a disclosed carbon-lithium material, while the second electrode material was carbon black,mesoporous carbon, graphitic carbon, or a combination thereof. In some experiments, the electrochemical cell had an ion-exchange membrane positioned in the center of the compartment, separating the aqueous solution in contact with the first electrode from the aqueous solution in contact with the second electrode.

[0105] Charge storage behavior was observed in the electrochemical cell the carbon-lithium material. Lithium intercalated within the graphitic carbon enhanced the carbon-lithium interface and enabled charge exchange between the embedded lithium and the electrolyte solution. Carbon-lithium samples displayed repeatable charge-discharge behavior when used as an electrode material in an electrochemical cell, as illustrated in FIG. 2D, which shows current output over time. The electrochemical cell with a first electrode made from the carbon-lithium material and the second electrode made from or including carbon black was able to output 1 .2 V when fully charged and lasted more than 2 hours on the discharge cycle with an output of ~0.8 mA. The system regained 1 V output after recharge and showed similar behaviors after recharge.

[0106] When mounted in an industrial-grade lithium-ion battery testing unit, the carbon-lithium composite material demonstrated rechargeability while maintaining performance. As shown in FIG. 3, the electrochemical cell with the carbon-lithium material electrode produced a 1.42 V output when fully charged, and can cycle for 27 hours when discharged. The same cell produced a 1.32 V output when fully charged again, and lasted another 20 hours and 30 minutes on a second discharge cycle. The cell was tested further and more than two chargedischarge cycles were achieved.

[0107] The voltage of the electrochemical cell with a first electrode made from the carbon- lithium material was between 0.5 V and 1.8 V. The cycle life of the electrochemical cell was between 5 cycles and 10 cycles. The cycle time of the electrochemical cell with a first electrode made from a carbon-lithium material is between 5 h and 30 h. The electrochemical cell was useful for portable energy storage applications, including small appliances, low-power applications, and / or short-term energy storage.

[0108] It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

Claims

CLAIMSWhat is claimed is:

1. An electrochemical cell comprising a first electrode comprising a carbon-lithium composite material; a second electrode; a compartment, wherein the compartment houses the first electrode and the second electrodes; and a network of lithium infused carbon tubes in contact with the first electrode and the second electrode, wherein the compartment contains the lithium-infused carbon tubes.

2. The electrochemical cell of claim 1 , further comprising a fluid in contact with the first electrode and the second electrode.

3. The electrochemical cell of claim 2, wherein the fluid comprises a liquid or a gas.

4. The electrochemical cell of claim 1 , wherein lithium in the lithium infused carbon tubes migrates from a first wall of the lithium infused carbon tubes towards a second wall of the lithium infused carbon tubes under influence of an applied field, and wherein the lithium undergoes a change in oxidation state from Li(0) to Li (I).

5. The electrochemical cell of claim 1 , wherein lithium in the carbon-lithium composite material is intercalated into the carbon-lithium composite material.

6. The electrochemical cell of claim 1 , wherein the second electrode comprises carbon black, mesoporous carbon, graphitic carbon, another electrically conductive material, or any combination thereof.

7. The electrochemical cell of claim 1 , wherein a voltage of the electrochemical cell is from about 0.5 V to about 10.8 V.

8. The electrochemical cell of claim 1 , wherein a cycle life of the electrochemical cell is from about 2 cycles to about 10 cycles.

9. The electrochemical cell of claim 1 , wherein a cycle time of the electrochemical cell is from about 5 h to about 30 h.

10. The electrochemical cell of claim 1 , wherein the carbon-lithium composite material has a specific surface area of from about 20 m2 / g to about 1060 m2 / g.

11. The electrochemical cell of claim 1 , wherein the carbon-lithium composite material comprises a plurality of repeating structures.

12. The electrochemical cell of claim 11 , wherein the plurality of repeating structures are spaced from about 0.5 nm apart to about 2 nm apart.

13. The electrochemical cell of claim 12 where the plurality of repeating structures form an electrically-conductive network.

14. The electrochemical cell of claim 1 , wherein the electrochemical cell comprises a circular, triangular, or rectangular geometric shape having at least one face, wherein the first electrode and the second electrode are on the same at least one face of the geometric shape.

15. A small appliance comprising the electrochemical cell of any one of claims 1-14.

16. The small appliance of claim 15, wherein the electrochemical cell is removable from the small appliance.

17. The small appliance of claim 15, wherein the small appliance comprises a smartphone, smart watch, laptop computer, tablet computer, electronic toy, an interactive display, or any combination thereof.

18. A method for short-term energy storage, the method comprising charging the electrochemical cell of any one of claims 1-14.

19. The method of claim 18, wherein charging the electrochemical cell is accomplished using a solar generator, a wind generator, or both a solar generator and a wind generator.

20. A method for producing a carbon-lithium composite material, the method comprising:(a) soaking a cellulosic material in a lithium salt solution to produce a cellulosic-lithium material;(b) drying the cellulosic-lithium material to produce a dried cellulosic-lithium material; and(c) pyrolyzing the dried cellulosic-lithium material to produce a carbon-lithium composite material.

21. The method of claim 20, wherein the cellulosic material comprises cellulose, hemicellulose, lignin, or any combination thereof.

22. The method of claim 20, wherein the cellulosic material is sourced from a plant or agricultural residue.

23. The method of claim 22, wherein the plant or agricultural residue comprises cotton, a hardwood, a softwood, sawdust, flax, hemp, sisal, lyocell, bamboo, corn, another grain, sugarcane bagasse, or any combination thereof.

24. The method of claim 20, wherein the lithium salt solution comprises an aqueous solution.

25. The method of claim 20, wherein the lithium salt solution comprises a lithium halide, a lithium carboxylate, lithium nitrate, lithium carbonate, or any combination thereof.

26. The method of claim 20, wherein the lithium salt comprises lithium chloride, the cellulosic material comprises cellulose, and the lithium salt solution comprises an aqueous solution.

27. The method of claim 20, further comprising performing surface modification on the cellulosic-lithium material after step (a).

28. The method of claim 27, wherein surface modification comprises silanization.

29. The method of claim 28, wherein silanization is conducted via chemical vapor deposition of a silane onto the cellulosic-lithium material.

30. The method of claim 29, wherein the silane comprises a trichloro(alkyl)silane.31 . The method of claim 30, wherein a hydrocarbon fragment of the trichloro(alkyl)silane comprises from about 1 to about 12 carbon atoms.

32. The method of claim 20, wherein the lithium salt solution further comprises an additive.

33. The method of claim 32, wherein the additive is present in an amount of from about 1 :3 to about 1 :20 relative to an amount of cellulose.

34. The method of claim 32, wherein the additive comprises dimethylacetamide (DMAc), an ionic liquid, or any combination thereof.

35. The method of claim 34, wherein the ionic liquid comprises 1-allyl-3-methylimidazolium chloride (AM I MCI), 1-ethyl-3-methylimidazolium acetate (EMIMAc), or any combination thereof.

36. The method of claim 20, wherein step (b) is carried out at from about 80 °C to about 150 °C.

37. The method of claim 20, wherein step (c) Is carried out at from about 300 °C to about 1500 °C.

38. A carbon-lithium composite material made by the method of any one of claims 20-37.

39. The carbon-lithium composite material of claim 38, wherein the carbon-lithium composite material has a specific surface area of from about 20 m2 / g to about 1060 m2 / g.

40. The carbon-lithium composite material of claim 38, wherein the carbon-lithium composite material comprises a plurality of repeating structures.

41. The carbon-lithium composite material of claim 40, wherein the plurality of repeating structures are spaced from about 0.5 nm apart to about 2 nm apart.

42. The carbon-lithium composite material of claim 40, wherein the plurality of repeating structures form an electrically-conductive network.

Images