Single ion conducting polymers for electrochemical devices
阅读说明：本技术 用于电化学装置的单离子导电聚合物 (Single ion conducting polymers for electrochemical devices ) 是由 M·阿曼德 M·马丁内兹-伊巴涅斯 E·桑切斯迪茨 A·圣地亚哥桑切斯 H·张 U·奥特奥 于 2020-12-02 设计创作，主要内容包括：本发明涉及一种固体单离子导电聚合物,其包含式(Ia)的重复单元,其中R～1是H、或C-1至C-(16)直链或支化烷基、烯基、炔基；m是1至5；各M～+独立地选自Li～+、Na～+或K～+；且X选自CF-3、CH-3或F；且所述聚合物具有350,000至1,200,000Da的平均分子量。(The present invention relates to a solid, single ion conducting polymer comprising a repeating unit of formula (Ia) wherein R 1 Is H, or C 1 To C 16 Linear or branched alkyl, alkenyl, alkynyl; m is 1 to 5; each M + Independently selected from Li + 、Na + Or K + (ii) a And X is selected from CF 3 、CH 3 Or F; and the polymer has an average molecular weight of 350,000 to 1,200,000 Da.)
1. A solid, single ion conducting polymer comprising a repeat unit of formula (Ia):
wherein R is1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl;
m is 1 to 5;
each M+Independently selected from Li+、Na+Or K+(ii) a And is
X is selected from CF3、CH3Or F;
and the polymer has an average molecular weight of 350,000 to 1,200,000 Da.
2. The solid, single ion conducting polymer according to claim 1, wherein the polymer has the formula (I)
Wherein
R1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl;
n is 85 to 3900;
m is 1 to 5;
each M+Independently selected from Li+、Na+Or K+；
X is selected from CF3, CH3, CBR3, CCl3, F, Cl, Br, H or OH.
3. The solid, single ion conducting polymer of claim 1 or 2, wherein R1 is a C10-C18 linear or branched alkyl group.
4. The solid, single ion conducting polymer of any preceding claim, wherein m is 2.
5. The solid, single ion conducting polymer of any of the preceding claims, wherein X is CF 3.
6. The solid, single ion conducting polymer of any preceding claim, wherein R1 is a C16 straight chain alkyl group, M is 2, M + is Li and X is CF3, and the polymer has an average molecular weight of 400,000Da to 1,000,000 Da.
7. A battery electrode comprising the solid, single ion conducting polymer of any one of claims 1 to 6.
8. The electrode of claim 7, wherein the electrode is a cathode further comprising a cathodic electroactive material, preferably selected from the group consisting of lithium cobalt oxide, lithium manganese nickel cobalt oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate or spinel, and optionally a conductive carbon.
9. The electrode of claim 7, wherein the electrode is an anode further comprising an anodic electroactive material and optionally conductive carbon, wherein the anodic electroactive material is preferably selected from graphite or carbon nanotubes, silicon, lithium titanate or tin oxide.
10. An electrode according to any one of claims 7 to 9, wherein the electrode comprises about up to 10 wt%, about up to 15 wt% or about up to 20 wt% of the solid single ion conducting polymer.
11. An electrode according to any one of claims 7 to 10, wherein the electrode is calendered at a temperature of 20 to 110 ℃.
12. An electrode according to any one of claims 7 to 11, wherein the electrode has a porosity of about 10% to about 50%.
13. An electrolyte for a battery comprising the solid, single-ion conducting polymer according to any one of claims 1 to 6.
14. A battery comprising a conductive polymer according to any one of claims 1 to 6, at least one electrode according to any one of claims 7 to 12 or an electrolyte according to claim 13.
15. A process for producing a solid, single-ion conducting polymer according to any one of claims 1 to 6, comprising the steps of:
a) providing a polymer of formula (II)
Wherein
R1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl; and is
n is 85 to 3900;
b) reacting the polymer with a compound of formula (III) under suitable conditions
Wherein
m is 1 to 5;
M+selected from Li+、Na+Or K+；
X is selected from CF3、CH3、CBR3、CCl3F, Cl, Br, H or OH.
Technical Field
The present invention is in the field of energy storage devices, in particular lithium-based energy storage devices, more particularly batteries (batteries). In particular, the present invention is in the field of ion conducting polymers and their use.
Background
The importance of batteries and other energy storage devices is growing rapidly. Next generation consumer electronics, such as smart phones, tablets, or laptops, are a part of almost everyone's life and it is desirable to have sufficient battery storage for long-term use. In addition, the rise of electric vehicles (e-mobility), particularly electronic-driven automobiles and electric scooters, requires a battery pack having high capacity and reasonable weight. Current research in battery technology is being conducted around new materials to improve the safety of batteries and to increase and optimize the volumetric and gravimetric energy density.
The most common rechargeable battery pack is the Li battery pack, which is used today for portable electronic products and even electric cars. Li batteries are now so important that the 2019 nobel prize in physics awarded the pioneer of this technology.
Lithium batteries are generally based on three basic components: two electrodes, an anode and a cathode, and an electrolyte. The anode is usually based on carbon, in most cases graphite, while the cathode is usually based on one of the three basic materials-layered oxide, polyanion or spinel. Since lithium is a highly reactive metal, the electrolyte is typically a non-aqueous liquid electrolyte based on a mixture of organic carbonates containing complexes of lithium or other alkali metal ions.
The advantages of these liquid nonaqueous electrolytes are high lithium ion conductivity and good solid-electrolyte interface formation. However, these electrolytes also exhibit significant drawbacks, such as being volatile and combustible. As such, defective or inappropriate lithium batteries using these liquid nonaqueous electrolytes pose a safety concern. Removing device
In addition to liquid electrolytes, lithium batteries are now also constructed using solid electrolytes.
One class of electrolytes that may be suitable alternatives are polymer electrolytes, which may provide significant advantages in terms of thermal and electrochemical stability. Another alternative is an inorganic solid electrolyte, which offers the advantage of better thermal stability at the expense of reduced flexibility.
One new class of polymer electrolytes is single ion conducting polymer electrolytes. These polymers are typically lithiated ionomers having poly (ethylene oxide) functional groups and associated anions (thermal anion). These electrolytes may exhibit high oxidative stability and support higher charge/discharge rates.
No single electrolyte is suitable for all applications. New electrolytes, particularly polymer electrolytes, exhibiting advanced or adjustable properties are being investigated.
Summary of The Invention
The present invention relates to novel single ion conducting polymers, their production and the use of said polymers in batteries. The novel polymers are suitable as electrolyte materials and can be used in the anode or cathode of rechargeable lithium batteries.
The novel polymers offer some advantages, in particular the possibility of adjusting the porosity of the electrodes using said polymers, thus enabling the volumetric energy density to be controlled.
Brief Description of Drawings
FIGS. 1A and 1B: reaction scheme for the Synthesis of the polymers of the invention
FIG. 2: performance of batteries Using the polymers of the invention
Detailed Description
The present invention relates to a solid, single ion conducting polymer comprising a repeat unit of formula (Ia):
wherein R is1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl (alkinyl);
m is 1 to 5;
each M+Independently selected from Li+、Na+Or K+(ii) a And is
X is selected from CF3、CH3Or F;
and the polymer has an average molecular weight of 350,000 to 1,200,000 Da.
In a particular embodiment, the present invention relates to solid, single ion conducting polymers of the general formula (I)
Wherein R is1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl;
n is 50 to 5000;
m is 1 to 5;
each M+Independently selected from Li+、Na+Or K+(ii) a And is
X is selected from CF3、CH3Or F.
The polymers of the invention are particularly suitable for rechargeable batteries, in particular lithium batteries. One particular advantage of the polymers of the invention is their porosity, which can be adjusted, for example, on the basis of the treatment during the preparation of the electrodes. Thus, the polymer enables the volumetric energy density of a battery comprising the solid single ion conducting polymer to be adjusted.
The invention further relates to a battery electrode comprising the solid mono-ionic conducting polymer of the invention and to a battery comprising the electrode of the invention or the polymer of the invention.
In a further aspect, the present invention relates to a process for producing the solid, single ion conducting polymer of the present invention.
Various aspects and embodiments of the invention are discussed in detail below.
In one aspect, the present invention relates to a solid, single ion conducting polymer comprising a repeat unit of formula (Ia):
wherein R is1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl;
m is 1 to 5;
each M+Independently selected from Li+、Na+Or K+(ii) a And is
X is selected from CF3、CH3Or F;
and the polymer has an average molecular weight of 350,000 to 1,200,000 Da.
In a particular embodiment, the present invention relates to solid, single ion conducting polymers of the general formula (I)
Wherein R is1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl;
n is 50 to 5000;
m is 1 to 5;
each M+Independently selected from Li+、Na+Or K+(ii) a And is
X is selected from CF3、CH3Or F.
R1May be H or straight or branched C1To C16Alkyl, alkenyl or alkynyl.
In a preferred embodiment, R1Is C1To C16Straight-chain or branched alkyl. Preferred is C1To C16Straight or branched chainAlkylated alkyl moieties (moieties) include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, isopropyl, C (CH)3)3. Preferably, the linear or branched alkyl group is selected from linear C1-C16Alkyl, preferably C1C8Straight-chain or branched alkyl, particularly preferably straight-chain unsubstituted C1 C8An alkyl group.
In some embodiments, R1Selected from methyl, ethyl, propyl, butyl or isopropyl. In a particularly preferred embodiment, R1Is methyl, ethyl or propyl, most preferably ethyl.
In some embodiments, m is an integer selected from 1,2, 3, 4, or 5. Preferably, m is 1,2 or 3. In a particularly preferred embodiment, m is 2.
In some embodiments, n is 200 to 1000. In a preferred embodiment, n is from 200 to 500.
In another embodiment, the solid, single ion conducting polymer has an average molecular weight of 400,000 to 1,000,000 Da.
X is preferably a halogen or a halogen-containing group. In a preferred embodiment, X is selected from CF3、CCl3、CBr3F, Cl or Br. In a particularly preferred embodiment, X is selected from CF3、CCl、CBr3Or CI3. In a particular embodiment, X is CF3。
In one embodiment, the present invention relates to a solid, single ion conducting polymer comprising a repeat unit of formula (Ia):
wherein
R1Is C8To C16An alkyl group;
M+selected from Li+Or Na+；
X is selected from CF3、CBR3、CCl3。
In a particular embodiment, the present invention relates to a solid, single ion conducting polymer comprising a repeat unit of formula (Ia):
wherein
R1Is C16An alkyl group;
M+is Li+；
X is CF3。
The solid single ion conducting polymers of the present invention have several advantageous properties. The polymers of the present invention are compatible with different electroactive materials. The polymer is therefore suitable as an electrolyte in a battery, as well as being part of an anode or cathode.
The solid single ion conducting polymer can be produced in several ways that will be apparent to those skilled in the art. In one aspect, the present invention relates to a process for producing a solid, single-ion conducting polymer according to the present invention.
The inventors have found that the polymers according to the invention can be produced by grafting the compounds of the formula (III) onto the polymers of the formula (II). Alternative methods for producing the polymers of formula (I) are known to the person skilled in the art.
In one embodiment, the present invention relates to a process for producing a solid, single ion conducting polymer of formula I as described above, comprising the steps of:
a) providing a polymer of formula (II)
Wherein
R1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl; and is
n is 85 to 3900;
b) reacting the polymer with a compound of formula (III)
Wherein
m is 1 to 5;
M+selected from Li+、Na+Or K+；
X is selected from CF3、CH3、CBR3、CCl3F, Cl, Br, H or OH.
R1、n、M+Preferred embodiments of m and X are the same preferred embodiments as the polymers as defined above.
Suitable reaction conditions for producing the polymers according to the invention are known to the person skilled in the art. In one non-limiting embodiment, the polymer of formula (II) is reacted with the compound of formula (III) in a suitable solvent under reflux conditions. In one embodiment, the solvent is Dimethylformamide (DMF) or DMSO. In general, any solvent in which the polymer is soluble is suitable.
In a further aspect, the invention relates to a battery comprising a solid mono-ionic conducting polymer as defined above and an electrode comprising said solid mono-ionic conducting polymer.
Accordingly, in one embodiment, the present invention relates to an electrode comprising a solid, single ion conducting polymer as described above. Preferably, the electrode is an electrode of a battery. However, the polymer may be used for any kind of electrode.
The electrode comprising the solid single ion conducting polymer according to the present invention may be any kind of electrode. In a battery, the electrode comprising the polymer may be the anode, the cathode, or both electrodes may comprise the polymer.
Accordingly, in one embodiment, the invention relates to an electrode, wherein the electrode is a cathode comprising a solid, single ion conducting polymer of formula I according to the invention. In a preferred embodiment, the cathode comprises a polymer according to the invention, an electroactive material, preferably a cathodic electroactive material and optionally conductive carbon.
In another embodiment, the invention relates to an electrode, wherein the electrode is an anode comprising a solid mono-ionic conducting polymer according to the invention, an electroactive material, preferably an anode electroactive material, and optionally a conductive carbon.
Non-limiting examples of conductive carbon include graphite, graphene, and carbon nanotubes.
The solid single ion conducting polymers according to the present invention can be used with essentially any electroactive material. In particular, the polymers of the present invention can be used with any cathodic electroactive material and any anodic electroactive material.
Non-limiting examples of cathodic electroactive materials include lithium cobalt oxide, lithium manganese nickel cobalt oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese oxide, and spinel.
Non-limiting examples of anode electroactive materials include graphite, carbon nanotubes, silicon/carbon composites, tin/cobalt alloys, and lithium titanate.
Accordingly, in one embodiment the invention relates to an electrode, in particular a cathode as defined above, wherein the cathode electrode material is selected from the group consisting of lithium cobalt oxide, lithium manganese nickel cobalt oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese oxide and spinel.
In another embodiment, the present invention relates to an electrode, in particular an anode as defined above, wherein the anode active material is selected from the group consisting of graphite, carbon nanotubes, silicon/carbon composites, tin/cobalt alloys and lithium titanate.
The appropriate amount of polymer according to the invention to be selected for the electrodes will be apparent to those skilled in the art. In some embodiments of the invention, an electrode comprising a solid single ion conducting polymer of the invention comprises up to 25% by weight of a polymer of the invention. In some embodiments, the electrode comprises about up to 10 wt%, about up to 15 wt%, or about up to 20 wt% of the solid single ion conducting polymer.
The use of the solid, single ion conducting polymers of the present invention is not limited to electrodes in batteries. In some embodiments, the invention relates to batteries comprising the solid single ion conducting polymers of the invention as solid electrolytes.
The inventors have surprisingly found that the solid, single ion conducting polymers of the invention can be calendered, thereby enabling the porosity of the polymer and hence of the electrodes, in particular of the cathode and anode. It is therefore possible to adjust the porosity of the electrode using the polymer of the present invention, thereby allowing, in particular, the energy density of a battery using the electrode to be adjusted.
Accordingly, in one embodiment, the invention relates to an electrode comprising the solid, single ion conducting polymer of the invention or a battery comprising said electrode, wherein said electrode is calendered.
The porosity of the polymer or electrode can be adjusted by calendering temperature. The inventors have found that if the electrode is rolled at a higher temperature, the porosity of the electrode is lower.
Accordingly, in one embodiment, the invention relates to an electrode comprising the solid, single ion conducting polymer of the invention or a battery comprising said electrode, wherein the electrode is calendered at a temperature of 20 to 110 ℃. In some embodiments, the electrode is calendered at 40 ℃, 60 ℃, 80 ℃, or 100 ℃.
The invention further relates to an electrode as defined above comprising a solid mono-ionic conducting polymer according to the invention, wherein the electrode has a porosity of at most 50%. In particular embodiments, the electrode has a porosity of about 10% to about 50%.
In a further embodiment, the invention relates to an electrolyte for use in a battery comprising a solid single ion conducting polymer as defined above.
The invention also relates to a battery comprising a solid mono-ionic conducting polymer as defined above, or at least one electrode as defined above or an electrolyte as defined above or a combination thereof.
In a further aspect, the invention relates to a method of producing an electrode (cathode or anode) of a battery, comprising the steps of:
a) providing a solid, single ion conducting polymer of the invention as defined above
b) Providing a cathodic or anodic electroactive material and optionally a conductive carbon
c) Combining the polymer and electroactive material and optionally conductive carbon
d) Optionally calendering the electrode.
The electrode may be rolled under the above conditions. In some embodiments, the electrode is calendered at a temperature of 20 to 110 ℃. In some embodiments, the electrode is calendered at 40 ℃, 60 ℃, 80 ℃, or 100 ℃.
The invention relates in particular to the following numbered items:
1. a solid, single ion conducting polymer comprising a repeat unit of formula (Ia):
wherein R is1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl;
m is 1 to 5;
each M+Independently selected from Li+、Na+Or K+(ii) a And is
X is selected from CF3、CH3Or F;
and the polymer has an average molecular weight of 350,000 to 1,200,000 Da.
2. The solid single ion conducting polymer according to item 1, wherein the polymer has the formula (I)
Wherein
R1Is H, or C1To C16Straight-chain or branchedAlkyl, alkenyl, alkynyl;
n is 85 to 3900;
m is 1 to 5;
each M+Independently selected from Li+、Na+Or K+；
X is selected from CF3、CH3、CBR3、CCl3F, Cl, Br, H or OH.
3. The solid single ion conducting polymer of item 1 or 2, wherein R1 is a C1-C18 linear or branched alkyl group.
4. The solid single ion conducting polymer of item 3, wherein R1 is a C10-C18 straight or branched alkyl group.
5. The solid single ion conducting polymer of any one of the preceding items, wherein m is 2.
6. The solid single ion conducting polymer of any one of the preceding items, wherein X is CF 3.
7. The solid single ion conducting polymer of any one of items 2 to 6, wherein n is 200 to 500.
8. The solid single ion conducting polymer of any one of the preceding items, wherein R1 is a C16 straight chain alkyl group, M is 2, M + is Li and X is CF3, and the polymer has an average molecular weight of 400,000Da to 1,000,000 Da.
9. A battery electrode comprising the solid, single ion conducting polymer of any one of items 1 to 8.
10. The electrode of item 9, wherein the electrode is a cathode, further comprising a cathodic electroactive material and optionally a conductive carbon.
11. The electrode of clause 10, wherein the cathodic electroactive material is selected from the group consisting of lithium cobalt oxide, lithium manganese nickel cobalt oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, or spinel.
12. The electrode of item 9, wherein the electrode is an anode further comprising an anodic electroactive material and optionally conductive carbon.
13. The electrode of item 12, wherein the anode electroactive material is selected from graphite or carbon nanotubes, silicon (silica), lithium titanate, or tin oxide.
14. The electrode of item 12 or 13, wherein the conductive carbon is graphite, graphene, or carbon nanotubes.
15. The electrode of any of clauses 9 to 14, wherein the electrode comprises up to 25 wt.% of the solid, single-ion conducting polymer.
16. The electrode of clause 15, wherein the electrode comprises about up to 10 wt.%, about up to 15 wt.%, or about up to 20 wt.% of the solid, single-ion conductive polymer.
17. The electrode of any of clauses 9 to 16, wherein the electrode is calendered.
18. The electrode of clause 17, wherein the electrode is calendered at a temperature of 20 to 110 ℃.
19. The electrode of clause 18, wherein the electrode is calendered at 40 ℃, 60 ℃, 80 ℃, or 100 ℃.
20. The electrode of any of clauses 9 to 19, wherein the electrode has a porosity of at most 50%.
21. The electrode of clause 20, wherein the electrode has a porosity of about 10% to about 50%.
22. An electrolyte for a battery comprising the solid single-ion conductive polymer according to any one of items 1 to 8.
23. A battery comprising a conductive polymer according to any one of items 1 to 8, at least one electrode according to any one of items 9 to 21, or an electrolyte according to claim 22.
24. The battery of clause 23, wherein the battery is a lithium or sodium battery.
25. A method for producing a solid single-ion conducting polymer according to any one of items 1 to 8, comprising the steps of:
a) providing a polymer of formula (II)
Wherein
R1Is H, or C1To C16Linear or branched alkyl, alkenyl, alkynyl; and is
n is 85 to 3900;
b) reacting the polymer with a compound of formula (III) under suitable conditions
Wherein
m is 1 to 5;
M+selected from Li+、Na+Or K+；
X is selected from CF3、CH3、CBR3、CCl3F, Cl, Br, H or OH.
Examples
Example 1: synthesis of solid single ion conducting polymers by grafting
The polymers of the present invention are prepared by grafting amine-terminated anions onto a maleic anhydride polymer backbone. First, amine-terminated anions were prepared from the reaction of aminosulfonyl chloride NR2(CH2) mSO2Cl and trifluoromethanesulfonamide CF3SO2NH2 in the presence of non-nucleophilic bases. Intermediates containing trifluoromethanesulfonimide containing non-nucleophilic ammonium cations are converted to the desired cation salt (usually lithium) by standard methods known in the state of the art. The amine-terminated anion is then grafted onto the maleic anhydride polymer backbone. Taking as an example a polymer having a chemical structure shown in scheme 1 (hereinafter abbreviated as polymer # 1), details of the synthesis are given below.
Scheme 1: structure of Polymer No. 1
1) Synthesis of amine-terminated anions
The synthetic procedure for lithium (2-aminoethanesulfonyl) (trifluoromethanesulfonyl) imide (liali) is described as an example in scheme 2; see also fig. 1A.
Scheme 2. Synthesis of lithium (2-aminoethanesulfonyl) (trifluoromethanesulfonyl) imide
A solution of taurine (20 g, 160 mmol) in aqueous NaOH (2M, 6.4 g, 1 eq, 160 mmol) was treated at 0 ℃ by dropwise addition of a solution of (Boc)2O (34.9 g, 1 eq, 160 mmol) in THF (25 ml). The mixture was stirred at room temperature (room temperature) for 15 hours and monitored by TLC for the disappearance of (Boc) 2O. The resulting mixture was extracted once with diethyl ether (80 ml). The aqueous phase was diluted with water (650 ml), treated with LiOH (3.8 g, 1 eq, 160 mmol) and n-Bu4Br (52.6 g, 1 eq, 160 mmol), and stirred at room temperature for 30 min. The resulting mixture was then extracted with dichloromethane (3 × 200 ml), the organic phase dried and evaporated under reduced pressure to give NBoc-taurine nBu4N. a salt.
N-Boc-taurine N-Bu was treated with DMF (2.2 mL) and then triphosgene (15.6 g, 0.4 eq, 52.5 mmol) at 0 deg.C4A solution of the salt (61.3 g, 131.3 mmol) in dichloromethane (340 ml) was then brought to room temperature with stirring. The reaction mixture was stirred at room temperature for an additional 60 minutes, then cooled to 0 ℃ and treated with a solution of DBU (42.0 g, 2.1 eq, 275.8 mmol) and CF3SO2NH2(29.4 g, 1.5 eq, 197.0 mmol) in dichloromethane (43 ml) by dropwise addition (20 minutes). These were mixed thoroughly beforehand at 0 ℃. The mixture was stirred at room temperature overnight (overlap) and then NH was used4Saturated aqueous Cl (2 × 100 ml) and brine (2 × 100 ml). The silica was added to the dichloromethane solution and then filtered off after stirring for 1 hour. The solvent was then partially removed in vacuo. Trifluoroacetic acid (28 ml, 7 eq, 367.0 mmol) was added at 0 ℃ and then allowed to reach room temperature. It was stirred for 1-2 hours. The product precipitates in the reaction medium. It was filtered and washed with dichloromethane. The product was isolated as a white powder. Trace CF can be removed by sublimation3SO2NH2. A solution of LiOH (2.3 g, 2 eq, 94.5 mmol) in H2O (160 mL) was added slowly. The reaction mixture was stirred at room temperature for 16 hours. The solvent was then removed in vacuo to yield a white solid. Excess LiOH was removed by redissolving in acetonitrile and filtering the undissolved LiOH. The solvent was removed in vacuo to yield a white powder of litat (12 g, 46 mmol).1H NMR(300MHz,D2O)δ(ppm)3,43(t,J＝6,6Hz,2H,S-CH2),3,15(t,J＝6,5Hz,2H,N-CH2)；19F-NMR(282MHz,D2O)δ(ppm)-78,54。
2) Grafting amine-terminated anions onto a polymer backbone
Scheme 3. Synthesis route for Polymer No. 1
This synthetic procedure is described in scheme 3; see also fig. 1B. To a solution of poly (ethylene-alt-maleic anhydride) in dimethylformamide (110 ml) was added 9 g of litat dissolved in 70 ml of dry dimethylformamide. The reaction was held at room temperature for 2 hours, at 50 ℃ for 2 hours, and at reflux (170 ℃) for 16 hours. Most of the solvent was removed under reduced pressure and the product was precipitated in THF (2 × 500 ml) and the resulting viscous solid was dialyzed against deionized water (dialyzed against deionized water). Water was removed under reduced pressure to give polymer # 1 (10 g, 25.7 mmol). 1H NMR (300MHz, D)2O)δ(ppm)4.09-3.68(m,2H,S-CH2),3.58-3.33(m,2H,N-CH2),2.78-2.52(m,2H,CH-CH),2.10-1.51(m,4H,CH-CH2-CH2).19F-NMR(282MHz,D2O)δ(ppm)-78.18。
Example 2: preparation of cathode for batteries Using Polymer # 1
By mixing 6.375 g NMC111 (LiNi) in a mortar1/3Mn1/3Co1/3O2) NMC cathode slurry was prepared with the powder and 0.375 grams of C-65 conductive carbon until a uniform dispersion was formed. In a vial 0.750 g of polymer # 1 was dissolved in 7 g of N-methyl-pyrrolidone (NMP) until complete dissolution. Adding NMC/C-65 mixture to binderlyte solution and mix for 2 minutes at 10K rpm. Subsequently, another 2 grams of NMP solvent (9 grams total NMP) was added. The resulting solution was mixed at 13k rpm for 20 minutes. The final slurry was degassed for 5 hours to eliminate possible bubbles generated during mixing.
The cathode was fabricated by coating the slurry on an aluminum current collector foil (current collector foil) and drying under vacuum at 100 ℃ overnight. The mass loading of the active material prior to calendering was 15mg/cm2To 19mg/cm2And, when not equal, the porosity was 46%.
The calendering procedure was carried out in a drying chamber at controlled temperatures (22 ℃ and dew point-60 ℃). The rolls were tempered at 100 ℃ for 1 hour. The laminate (laminate) passed through each selected roller opening four times (twice per direction) at a speed of 0.4 m/min. A first gap between the rolls was chosen close to the laminate thickness (76 μm) and gradually reduced later (56 μm and 46 μm). The calendering pressure was controlled to be lower than 43 tons. The laminate was punched with a 12mm diameter hole using an automatic punch and dried under vacuum at 50 ℃ overnight. The mass loading of the rolled active material was 15mg/cm2To 19mg/cm2The porosity varied to 24%.
Example 3: effect of calendering temperature on cathode porosity
The cathodes were prepared as described above using different temperatures of the rolls during calendering. The following table shows the porosity vs calendering temperature for the calendered cathode:
calendering temperature
Porosity in%
Without calendering
46±2
40℃
39±2
80℃
36±2
100℃
24±2
Example 4: preparation of batteries Using cathodes comprising Polymer # 1
The button cell (coin cell) is made of LiNi1/3Mn1/3Co1/3O2(NMC111) as the active material of the positive electrode and lithium metal as the negative electrode composition. The cathode was prepared as described above and calendered at 100 ℃. The electrolyte for button cell preparation contains 1mol/L LiPF in a 1:1 solvent mixture by volume of Ethylene Carbonate (EC) and Ethyl Methyl Carbonate (EMC)6. Use of2400 microporous membranes were used as separators.
The button cells were assembled according to the configuration in a glove box filled with argon. The NMC cathode (12mm diameter) was wetted with 80 microliters of electrolyte solution. On top of that, a 16mm diameter Celgard 2400 membrane was used as a separator between the electrodes. The NMC111 electrode was paired with a lithium metal disk of 14mm diameter and 500 μm thickness. Stainless steel gaskets and springs were added to the cells prior to sealing.
The theoretical capacity of NMC111 was fixed at 150 mAh/g. The cells were evaluated at different C rates (C-rates) using a Maccor Battery Tester (4000 series) in an oven at 25 ℃. The procedure for testing the cells was as follows.
The stack was first allowed to stand at 25 ℃ for 24 hours, and then held at a constant charge rate (charging rate) of 0.2C, with the discharge rate (discharge rate) being gradually changed as follows: 5 cycles at 0.2C, 5 additional cycles at 0.5C, 5 additional cycles at 1C, 5 cycles at 2C, 5 cycles at 5C, 5 cycles at 10C, and 5 cycles at 0.5C. An example of the performance of a battery using this cycling procedure is shown in fig. 2.