A sodium, lithium or potassium aqueous battery, and a method of manufacturing such a battery

Abstract

The present invention relates in a first aspect to an aqueous sodium, lithium or potassium ion battery comprising a counter electrode, an electrolyte in contact with the counter electrode, an working electrode in contact with the electrolyte and electrically isolated from the counter electrode. The counter electrode comprises a source of sodium, lithium or potassium atoms. The electrolyte comprises an aqueous solution of a sodium, lithium, or potassium salt. The working electrode comprises a porous carbon impregnated with an active material from the Quinone family. The present invention relates in a second aspect to an aqueous sodium, lithium or potassium ion battery wherein the working electrode is coated with a coating agent such as sodium alginate which is crosslinked with a crosslinking agent. The present invention further relates to a method of manufacturing such a battery comprising impregnating of the porous carbon with the active material and / or providing coating of a crosslinked coating agent on the working electrode.

Description

[0001] TITLE A sodium, lithium or potassium aqueous battery, and a method of manufacturing such a battery

[0002] TECHNICAL FIELD

[0003] The present invention relates to a sodium, lithium or potassium aqueous battery.

[0004] The invention further relates to methods of manufacturing such a battery.

[0005] BACKGROUND

[0006] The necessary energy transition that is required to limit global warming is ongoing, but there are many obstacles that still need to be taken. One of them is energy storage. The highly intermittent generation behaviour of the renewable electricity sources (solar and wind) requires electricity storage in order to store it when there is a surplus and deliver it when there is a shortage. The time period of electricity storage ranges from short term (miliseconds-hours) to long term (days-months).

[0007] Batteries are a promising solution for the short term storage as they can respond very rapidly and they have a high energy efficiency. They can for example be used for compensating the fast fluctuations in the electricity grid. Another application can be daily storage of solar electricity, in which the electricity is stored during the day and provided when the sun is down. All these applications require significant batteries which should (ideally) be made from renewable, cheap, intrinsically safe and non-toxic materials.

[0008] Lithium-ion batteries are the most used type of batteries at the moment. However, lithium is not abundantly available, the batteries comprise a highly flammable, toxic organic electrolyte and their electrodes consist of hazardous electrode materials like Nickel Manganese Cobalt (NMC) or Lithium Cobalt Oxide (LCO).

[0009] The main candidate that seems to be promising to replace Lithium is Sodium as it has many similarities and it is widely available in the sea and in many salts. The toxicity and flammability of the electrolyte can be eliminated by using an aqueous electrolyte. The sustainability of the battery can further be enhanced by using non-toxic organic electrode materials, which are preferable made from renewable sources like organic waste or bacteria. Incorporating these three substitutions result in an aqueous sodium-ion battery with organic electrodes.

[0010] Materials from the Quinone family seem to be suitable active materials for the working electrode (e.g. the negative electrode I anode). The main core of the Quinone family consists of an aromatic ring with one or multiple carbonyl groups attached to them. During charging of the battery, the carbonyl groups undergo an enolization reaction in which they make ‘semi-bonds’ with alkali ions (e.g. Li+, Na+and K+) via a redox reaction and rearrangement of the pi-bonds in the aromatic ring. This aromatic ring stabilizes the structure. The corresponding redox potentials are within or just outside the stability window of water, making the Quinones very suitable to be used in an aqueous electrolyte.

[0011] CN104795567 A discloses relates to an aqueous lithium-ion or sodium-ion battery with an organic compound monomer or organic polymer anode. A quinone was used as a negative electrode active material.

[0012] CN 104795566 discloses a battery with a negative electrode active material based on a quinone structure, a preparation method and an application of the battery negative electrode active material.

[0013] Experimental usage of Quinones in aqueous batteries shows that Quinones dissolve rapidly in the electrolyte when they are being charged (addition of the alkali ions). This means that less or no Quinone material (and thus capacity) is available anymore after some time to store electricity. Therefore modifications to the Quinones or the prepared electrode are required to supress the dissolution of them into the aqueous electrolyte. Polymerizations are effective, but it creates agglomerations which makes the processing of the Quinones very hard and their capacity is significantly lowered.

[0014] SUMMARY

[0015] It is an object of the present invention to provide an improved battery.

[0016] It is a further object of the present invention to provide an aqueous sodium, lithium or potassium ion battery with improved cyclability.

[0017] It is a further object of the present invention to provide an aqueous sodium, lithium or potassium ion battery that is intrinsically safe and fully renewable.

[0018] Therefore, the present invention relates in a first aspect to an aqueous sodium, lithium or potassium ion battery comprising a counter electrode, an electrolyte in contact with the counter electrode, an working electrode in contact with the electrolyte and electrically isolated from the counter electrode. The counter electrode comprises a source of sodium, lithium or potassium atoms. The electrolyte comprises an aqueous solution of a sodium, lithium, or potassium salt. The working electrode comprises a porous carbon impregnated with an active material from the Quinone family.

[0019] The present invention relates in a second aspect to an aqueous sodium, lithium or potassium ion battery comprising a counter electrode, an electrolyte in contact with the counter electrode, an working electrode in contact with the electrolyte and electrically isolated from the counter electrode. The counter electrode comprises a source of sodium, lithium or potassium atoms. The electrolyte comprises an aqueous solution of a sodium, lithium, or potassium salt. The working electrode is coated with a coating agent which is crosslinked with a crosslinking agent. This coating agent may be sodium alginate.

[0020] The present invention relates in a third aspect to a method of manufacturing a battery according to the first aspect, the method comprising impregnating of the porous carbon with the active material by a method comprising the steps of dissolving the active material in a solvent together with the porous carbon to obtain a suspension, ultrasonicating the obtained suspension to obtain a homogeneous suspension, and evaporating the solvent to obtain a porous carbon impregnated with the active material.

[0021] The present invention relates in a fourth aspect to a method of manufacturing a battery according to the first aspect, the method comprising providing a coating on the working electrode by contacting the working electrode with a coating agent, and subsequently contacting the working electrode with a crosslinking agent.

[0022] Embodiments of the battery according to the first aspect are applicable correspondingly to the method of manufacturing according to the second, third or fourth aspect of the present invention.

[0023] Without wishing to be bound by theory, the inventor believes that impregnation of a Quinone family member into a porous carbon seems to be effectively reducing the solubility of the quinone into the electrolyte during electrochemically cycling. BRIEF DESCRIPTION OF DRAWINGS

[0024] The present invention is described hereinafter with reference to the accompanying drawings in which embodiments of the present invention are shown and in which like reference numbers indicate the same or similar elements.

[0025] Fig. 1 shows electrochemical performances of a non-treated AQ- electrode. Fig. 1A shows charge and discharge profiles and Fig. 1 B shows cycling performance at a constant current (25,7 mA / g, C / 10).

[0026] Fig. 2 shows pictures of the non-treated AQ in an electrode (A) fresh battery (B) cycled for one time.

[0027] Fig. 3 is a schematic illustration of the coating procedure according to the fourth aspect of the present invention.

[0028] Fig. 4 shows electrochemical performances of a coated AQ-electrode with cross-linked sodium alginate with Ba2+. Fig. 4A shows charge and discharge profiles and Fig. 4B shows cycling performance at a constant current (25,7 mA / g, C / 10).

[0029] Fig. 5 is a schematic illustration of the impregnation method according to the third aspect of the present invention.

[0030] Fig. 6 shows X-Ray powder diffraction of pristine AQ, pristine activated carbon and the ratios 1 :2 and 1 :3.

[0031] Fig. 7 shows electrochemical performances of AQ impregnated in CMK-3 (ratio 1 :3). Fig. 7A shows charge and discharge profiles and Fig. 7B shows cycling performance at a constant current (25,7 mA / g, C / 10).

[0032] Fig. 8 shows electrochemical performances of AQ impregnated in meso-porous CMK-3 (ratio 1 :3). Fig. 8A shows charge and discharge profiles and Fig. 8B shows cycling performance all at a constant current (257 mA / g, 1C).

[0033] Fig. 9 shows electrochemical performances of AQ impregnated in ‘Porous Carbon’ (ACS Materials, ratio 1 :3). Fig. 9A shows charge and discharge profiles and Fig. 9B shows cycling performance all at a constant current (257 mA / g, 1C).

[0034] Fig. 10 shows electrochemical performances of AQ impregnated in activated carbon (ratio 1 :3). Fig. 10A shows charge and discharge profiles and Fig. 10B shows cycling performance all at a constant current (257 mA / g, 1C). DESCRIPTION OF EMBODIMENTS

[0035] As stated above, the present invention relates in a first aspect to an aqueous sodium, lithium or potassium ion battery comprising: a counter electrode comprising a source of sodium, lithium or potassium atoms; an electrolyte in contact with the counter electrode, wherein the electrolyte comprises an aqueous solution of a sodium, lithium, or potassium salt; and an working electrode comprising a porous carbon impregnated with an active material from the Quinone family, wherein the working electrode is in contact with the electrolyte and electrically isolated from the counter electrode.

[0036] The skilled person will appreciate that in case the battery is a sodium aqueous battery, the counter electrode will comprise a source of sodium atoms, and the electrolyte will comprise an aqueous solution of a sodium salt. In other words, the electrolyte will comprise the a solution of a salt corresponding to the ion source in the counter electrode (i.e. lithium salt with a counter electrode comprising a lithium ion source, and potassium salt with a counter electrode comprising a potassium ion source).

[0037] Where it is said that the counter electrode comprises a source of sodium, lithium or potassium atoms, this can also be understood to mean that the counter electrode functions as a source of sodium, lithium or potassium.

[0038] In the context of the present description, “working electrode” is used to refer to what is known in research as the electrode of interest. This is done to investigate the performances of this electrode only by oversizing the other electrode, the counter electrode. The working electrode can be the positive (cathode) as well as the negative (anode) electrode, depending on the working potential of the active material of interest. Both electrodes (positive and negative) are working electrodes in a full optimized battery. The presented results and proof of the prevention methods in this patent application are obtained by using AQ-electrodes as working electrodes. The working potential of AQ is relatively low and is thus used as anode in this case, but it is thus not necessarily limited to that. “Counter electrode” in the context of the present description is used to refer to what is known in research as the other necessary electrode that is not of interest during determining the performances of the working electrode. It usually also functions as the source of sodium, lithium or potassium atoms. In this claim the counter electrode material is Nao.44Mn02, which has a high work potential which is regarded as the cathode in this claim. But it is not necessarily limited to this configuration as well.

[0039] Examples of counter electrode materials that act as sources of sodium atoms are NaxMnO2 (with 0.18<x<0.80), NaxNiFe(CN)e (with 0<x<1), NaxCuFe(CN)e (with 0<x<1) and NaxCuyNii.yH(CN)6 (with 0<x,y<1). Examples of sources of lithium atoms are Li2Mn2O4, LiCoO2, LiFePO4. Examples of sources of potassium atoms are KxNiFe(CN)e (with 0<x<1) and KxCuFe(CN)e (with 0<x<1).

[0040] Examples of sodium salts are Na2SO4, NaCI, NaNOs and NaCIC . Examples of lithium salts are U2SO4, LiCI, UNO3 and UCIO4. Examples of potassium salts are KNO3 and KPFe.

[0041] In an embodiment of the battery according to the present invention, the active material from the Quinone family is selected from 1 ,2-benzoquinone, 1 ,4- benzoquinone, 1 ,4-naphtoquinone, 1 ,2- anthraquinone, 1 ,4- anthraquinone, and 2,6- anthraquinone, 9,10-anthraquinone, hydroquinone, anthraquinone-2,6-disulfonic acid disodium salt, and anthraquinone-2-sulfonic acid sodium salt, preferably wherein the active material is 9, 10-anthraquinone. In a specific embodiment, the active material is 9, 10-anthraquinone.

[0042] In an embodiment, the porous carbon is an activated carbon or a mesoporous carbon. An example of a mesoporous carbon is CMK-3. In a specific embodiment, the porous carbon is an activated carbon.

[0043] In an embodiment, the working electrode is coated with a coating agent which is crosslinked with a crosslinking agent. In a specific embodiment of this, the coating agent is a sodium alginate. This crosslinked coating may for instance have a thickness between 10-300 pm. For example, the thickness of the coating is between 100-300 pm, such as 200 pm. Without wishing to be bound by theory, the present inventor believes that providing a crosslinked (sodium alginate) coating on and / or in the working electrode further reduces the solubility of the quinone into the electrolyte during electrochemical cycling. There is an unexpected synergy between these two treatments, leading to a battery with a highly improved cyclability.

[0044] In an embodiment, the working electrode further comprises a binder, selected from polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) and sodium alginate, cross-linked with a crosslinking agent. In a specific embodiment, the binder is sodium alginate. Sodium alginate is a better ionic conductor of Na+,Li+and K+ions. In this context, sodium alginate may be alginic acid sodium salt. This salt may have for instance a viscosity of 4 to 1000 mPa (corresponding to a 1% solution). The concentration of the sodium alginate may for instance be from 0.5 to 10 wt.%. For example, the sodium alginate may have a viscosity of 8 mPa and / or a concentration of 5 wt.%.

[0045] The crosslinking agent may be a multivalent ion, such as one of barium (Ba2+), copper (Cu2+), calcium (Ca2+), iron (Fe2+and Fe3+), manganese (Mn2+and Mn3+), and aluminum (Al3+). In a specific embodiment, the crosslinking agent is barium (Ba2+). This Ba2+may for instance be from an aqueous solution of BaCh The concentration is barium may for instance be 0.5 M.

[0046] In an specific embodiment, the active material from the Quinone family is 9,10-anthraquinone, the porous carbon is activated carbon, the coating agent is sodium alginate, and the crosslinking agent is barium (Ba2+).

[0047] In an embodiment, the working electrode further comprises an electronic conductor that is not porous carbon. In the battery according to the present invention, it is possible that the porous carbon also serves as the electronic conductor. However, the presence of (another) electronic conductor may allow for instance higher (dis)charge rates. This additional conductor may be a specific carbon like carbon black.

[0048] In an embodiment, the battery is a sodium aqueous battery. In a specific embodiment of this, the counter electrode comprises Nao.44Mn02 as the active material. Another examples of suitable active materials for the counter electrode are NaxNiFe(CN)e (with 0<x<1), NaxCuFe(CN)6 (with 0<x<1) and NaxCuyNii.yH(CN)6 (with 0<x,y<1).

[0049] As stated above, the present invention relates in a second aspect to an aqueous sodium, lithium or potassium ion battery comprising: a counter electrode comprising a source of sodium, lithium or potassium atoms; an electrolyte in contact with the counter electrode, wherein the electrolyte comprises an aqueous solution of a sodium, lithium, or potassium salt; and an working electrode comprising a porous carbon impregnated with an active material from the Quinone family, wherein the working electrode is coated with a coating agent.

[0050] As stated above, the present invention relates in a third aspect to a method for manufacturing a battery according to the first aspect, the method comprising impregnating of the porous carbon with the active material by a method comprising the following steps: dissolving the active material in a solvent together with the porous carbon to obtain a suspension, ultrasonicating the obtained suspension to obtain a homogeneous suspension, and evaporating the solvent to obtain a porous carbon impregnated with the active material.

[0051] The solvent can be for instance DMSO. This is a suitable solvent for 9, 10-anthraquinone which can be used as active material for the working electrode of the aqueous batteries.

[0052] As stated above, the present invention relates in a fourth aspect to a method for manufacturing a battery according to the first aspect, the method comprising providing a coating on the working electrode by a method comprising the following steps: contacting the working electrode with a coating agent, the coating agent being sodium alginate, and subsequently contacting the working electrode with a crosslinking agent.

[0053] Contacting the working electrode with a coating agent may be for instance performed by adding a layer or by dip coating.

[0054] Contacting the working electrode with a crosslinking agent may for instance be done by dipping the electrode in a solution comprising the crosslinking agent.

[0055] In an embodiment of this aspect, the coating agent is sodium alginate, and / or the crosslinking agent is barium (Ba2+).

[0056] The methods of the third and fourth aspect can also be combined in one method of manufacturing a battery according to the first aspect, wherein the impregnation of the porous carbon takes place prior to coating of the working electrode with crosslinked sodium alginate.

[0057] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope thereof.

[0058] The scope of the present invention is defined by the appended claims. One or more of the objects of the invention are achieved by the appended claims.

[0059] EXAMPLES

[0060] The present invention is further elucidated based on the Examples below which are illustrative only and not considered limiting to the present invention.

[0061] Materials used

[0062] The material of interest, the active material of the working electrode for providing the evidence below was Anthraquinone (AQ, 97%, Sigma Aldrich). The active material within the counter electrode was Nao.44Mn02. This material acted as the sodium source for the working electrode, so its capacity was oversized (~5x) compared to the theoretical capacity of the working electrode active material in order to make the working electrode the limiting electrode.. Carbon Black (Super C45, TimCal) was used in both electrodes to enhance the electronic conductivity. Cross-linked sodium alginate (J61887, Alfa Aeser) with Ba2+ions and polyvinylidene fluoride (PVDF, SOLEF 21216, Solvay) were used as binders for the counter electrode and working electrode respectively. An Ag / AgCI reference electrode (Sigma Aldrich) was used in order to monitor the individual half-cell potentials of the working electrode and counter electrode.

[0063] Non-treated

[0064] The electrochemical performances of non-treated Anthraquinone (AQ) electrode can be seen in Fig. 1. Fig. 1 shows electrochemical performances of a non-treated AQ-electrode. Fig. 1A shows charge and discharge profiles and Fig. 1 B shows cycling performance at a constant current (25,7 mA / g, C / 10). It can be seen that all material is able to be fully used / charged (theoretical capacity of AQ is 257 mAh / g). Only a small fraction of the initial material is able to discharge (~8%, 20 mAh / g) and it decreases in the sequential cycles. This is mainly due to the dissolution of the sodiated AQ, which is very soluble. This can visually be seen in Fig. 2: the aqueous electrolyte is colourless on its own (non-used) and turns yellowish (colour of AQ) already after one charge and discharge. Fig. 2 shows pictures of the non-treated AQ in an electrode (A) fresh battery (B) cycled for one time.

[0065] Crosslinked coating

[0066] The dissolution of AQ into the electrolyte can partly be prevented by applying a coating (made of cross-linked sodium alginate with Ba2+ions) on top of a similar AQ-electrode as above. This coating process is illustrated in Fig. 3. The sodium alginate (coating agent, Alfa Aeser) is dissolved in demi-water (1) where after it is casted on the electrode (2) with a doctor blade (3) (or a similar device with a slid) to obtain a specific thickness (5). The whole electrode is than dipped in an aqueous solution of barium chloride (crosslinking agent, Alfa Aeser) for 15 min to establish the Ba2+-crosslinking with the sodium alginate.

[0067] The electrochemical performances of an AQ-electrode coated with cross-linked sodium alginate with Ba2+, Fig. 4, shows that a significant higher fraction (-52%, 132 mAh / g) is able to discharge in the second cycle as well as in the 50thcycle (-20%, 52 mAh / g) than that with the non-treated AQ electrode. Fig. 4 shows electrochemical performances of a coated AQ-electrode with cross-linked sodium alginate with Ba2+. Fig. 4A shows charge and discharge profiles and Fig. 4B shows cycling performance at a constant current (25,7 mA / g, C / 10). These results shows that the coating is able to supress the dissolution to a certain extend.

[0068] Porous carbon

[0069] A method that effectively supresses the dissolution of AQ is the impregnation of AQ in a porous carbon. This impregnation method is illustrated in Fig. 5, in which CMK-3, activated carbon or any porous carbon is (1), AQ is the active material (2) in this experimental section and Dimethylsulfoxide (DMSO) is the solvent (3). The ratio between the active material and porous carbon influences whether or not there is active material left on the surface of the porous carbons, or that everything is inside the pores. Any material on the surface will still be able to dissolve in a similar way as in the non-treated AQ-electrode. This can be checked by performing X-Ray powder diffraction on it, see Fig. 6. Fig. 6 shows X-Ray powder diffraction of pristine AQ, pristine activated carbon and the ratios 1 :2 and 1 :3. As can be seen, a ratio of 1 :2 (in this case AQ:activated carbon) is still shows some AQ on the surface of activated carbon. With a ratio of 1 :3 this is not the case. The impregnation of AQ in a porous carbon (below illustrated with CMK-3, a mesoporous carbon) activated carbon significantly reduces the dissolvability of AQ into the aqueous electrolyte. Fig. 7 Shows the electrochemical performances of AQ impregnated in CMK-3 (ratio 1 :3). Fig. 7A shows charge and discharge profiles and Fig. 7B shows cycling performance at a constant current (25,7 mA / g, C / 10). These electrochemical performances show similarities with that of the AQ-electrode with the coating. The fraction that can be discharged in the second cycle is 53% (135 mAh / g) and 19% (48 mAh / g) for the 50thcycle. This partly supresses the dissolution of AQ.

[0070] Porous carbon in combination with crosslinked

[0071] Applying the impregnation of AQ in a porous carbon and applying the coating of the sequential electrode together stops the dissolution of AQ very effectively. This is illustrated in Fig. 8, Fig. 9 and Fig. 10 in which three different porous carbons are used. Fig. 8 shows electrochemical performances of AQ impregnated in meso-porous CMK-3 (ratio 1 :3). Fig. 8A shows charge and discharge profiles and Fig. 8B shows cycling performance all at a constant current (257 mA / g, 1C). Fig.9 shows electrochemical performances of AQ impregnated in ‘Porous Carbon’ (ACS Materials, ratio 1 :3). Fig. 9A shows charge and discharge profiles and Fig. 9B shows cycling performance all at a constant current (257 mA / g, 1C). Fig. 10 shows electrochemical performances of AQ impregnated in activated carbon (ratio 1 :3). Fig. 10A shows charge and discharge profiles and Fig. 10B shows cycling performance all at a constant current (257 mA / g, 1C).

[0072] The porous carbon in Fig. 8 is mesoporous CMK-3 provided by ACS Materials, in Fig. 9 it is ‘Porous carbon’ provided by ACS Materials and in Fig. 10 it is activated carbon provided by Sanwa Components. In all three figures it can be seen that capacities are still moderate after several thousands of cycles despite decays (which is characteristic for batteries). This implies that AQ is still present and that the dissolution is greatly prevented. This shows that there is an unexpected synergy between the use of an impregnated porous carbon and a crosslinked coating agent such as, in these examples, sodium alginate.

Claims

CLAIMS1. An aqueous sodium, lithium or potassium ion battery comprising: a counter electrode comprising a source of sodium, lithium or potassium atoms; an electrolyte in contact with the counter electrode, wherein the electrolyte comprises an aqueous solution of a sodium, lithium, or potassium salt; and a working electrode comprising a porous carbon impregnated with an active material from the Quinone family, wherein the working electrode is in contact with the electrolyte and electrically isolated from the counter electrode.

2. The battery according to any of the preceding claims, wherein active material from the Quinone family is selected from 1 ,2-benzoquinone, 1 ,4- benzoquinone, 1 ,4-naphtoquinone, 1 ,2- anthraquinone, 1 ,4- anthraquinone, and 2,6- anthraquinone, 9, 10-anthraquinone, hydroquinone, anthraquinone-2,6-disulfonic acid disodium salt, and anthraquinone-2-sulfonic acid sodium salt, preferably wherein the active material is 9,10-anthraquinone.

3. The battery according to any of the preceding claims, wherein the porous carbon is an activated carbon or a mesoporous carbon, preferably wherein the porous carbon is an activated carbon.

4. The battery according to any of the preceding claims, wherein the working electrode is coated with a coating agent which is crosslinked with a crosslinking agent.

5. The battery according to claim 4, wherein the coating agent is a sodium alginate.

6. The battery according to claim 4 or 5 wherein the crosslinked coating has a thickness between 10-300 pm.

7. The battery according to any of the preceding claims, wherein the working electrode further comprises a binder, selected from polyvinylidene fluoride(PVDF), polytetrafluoroethylene (PTFE) and sodium alginate, cross-linked with a crosslinking agent; preferably wherein the binder is sodium alginate.

8. The battery according to any of the claims 4-7, wherein the crosslinking agent is a multivalent ion, preferably selected from barium (Ba2+), copper (Cu2+), calcium (Ca2+), iron (Fe2+and Fe3+), manganese (Mn2+and Mn3+), and aluminum (Al3+), more preferably the crosslinking agent is barium (Ba2+).

9. The battery according to any claims 4-8, wherein the active material from the Quinone family is 9,10-anthraquinone, wherein the porous carbon is activated carbon, wherein the coating agent is sodium alginate, and the crosslinking agent is barium (Ba2+).

10. The battery according to any of the preceding claims, wherein the battery is a sodium aqueous battery.

11. The battery according to any of the preceding claims, wherein the counter electrode comprises Nao.44Mn02 as the active material.

12. Method for manufacturing a battery according to any of the preceding claims, the method comprising impregnating of the porous carbon with the active material by a method comprising the following steps: dissolving the active material in a solvent together with the porous carbon to obtain a suspension, ultrasonicating the obtained suspension to obtain a homogeneous suspension, and evaporating the solvent to obtain a porous carbon impregnated with the active material.

13. Method for manufacturing a battery according to any of claims 4-11 , the method comprising providing a coating on an electrode, preferably the working electrode, by a method comprising the following steps:Contacting the electrode with a coating agent, and subsequently Contacting the electrode with a crosslinking agent.

14. The method according to claim 13, wherein the coating agent is sodium alginate, and / or wherein the crosslinking agent is barium (Ba2+).

15. Method for manufacturing a battery according to any of claims 1-11 , the method comprising impregnating of the porous carbon with the active material according to claim 12, and subsequently providing a coating on the electrode according to claim 13 or 14.

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