Electrolyte containing hydrogen anion compound and alkali metal battery

Abstract

The invention discloses an electrolyte containing a hydrogen anion compound and an alkali metal battery, and belongs to the technical field of alkali metal batteries. The electrolyte includes a) an alkali metal salt; b) a non-aqueous organic solvent; and c) an additive which comprises a hydrogen anion compound and forms a dihydrogen bond with the non-aqueous organic solvent. The alkali metal battery comprises a positive electrode material, a negative electrode material, a diaphragm and the electrolyte containing the hydrogen anion compound. According to the electrolyte disclosed by the invention, the dihydrogen bonds are formed, the orientation of the non-aqueous organic solvent in Helmholtz layers (IHP) in the positive electrode and the negative electrode is adjusted, active hydrogen atom (H delta +) sites which are easy to oxidize under high voltage are shielded, and the oxygenolysis of the non-aqueous organic solvent is remarkably inhibited, so that the oxidation stability of the electrolyte is expanded. And high stability and excellent high-temperature performance under high voltage are realized.

Description

Technical Field

[0001] This invention belongs to the field of alkali metal battery technology, and more specifically, relates to an electrolyte containing a hydrogen anion compound and an alkali metal battery. Background Technology

[0002] Driven by the deepening global "dual-carbon" strategy and the rapid development of the new energy vehicle industry, the energy density of power batteries has become a key technological bottleneck restricting the long driving range (>1000 km) of electric vehicles. High-voltage lithium metal batteries (LMBs) are particularly advantageous due to their high theoretical specific capacity (3860 mAh·g). -1 Alkali metal batteries, with their high energy density and high voltage characteristics, are considered one of the most promising next-generation energy storage technologies. Sodium metal batteries (SMBs), due to their abundant resources, low cost, and similar working mechanism to LMBs, have rapidly become a research hotspot. Alkali metal batteries with higher energy density are the inevitable trend.

[0003] However, the practical application of high-voltage alkali metal batteries is still constrained by challenges such as lithium / sodium dendrites, interface instability, and high-voltage electrolyte decomposition, which significantly reduce cycle life and safety performance. Developing novel electrolytes, optimizing electrode materials, and innovating battery structures have become urgent priorities.

[0004] A search revealed Chinese patent application number 202410452869.3, published on May 17, 2024, which discloses a wide-temperature electrolyte for alkali metal secondary batteries. This patented electrolyte is composed of a main solvent, a hydrogen bond donor solvent, and an alkali metal electrolyte salt. The hydrogen bond donor solvent includes N... Methyl-p-fluoroaniline, 2 Nitropyrrole, 2 Nitroimidazole, furfuryl mercaptan, p-fluorophenol, 2,4,6 Trifluoroaniline or N The electrolyte comprises one or more of methyltrifluoroformamides; the main solvent is one or more of cyclic / linear carbonate solvents or cyclic / linear organic ether solvents; the alkali metal electrolyte salt is one or more of lithium salt, sodium salt, or potassium salt; the hydrogen bond donor solvent accounts for 1wt% to 50wt% of the total mass of the electrolyte, and the concentration of the alkali metal electrolyte salt in the electrolyte is 0.5 to 3 mol / L. However, this patent optimizes the solvation structure and interfacial film formation through a molecular engineering strategy (hydrogen bond donor). Its core is to introduce hydrogen bond donor solvents, such as N-methyl-p-fluoroaniline and 2-nitropyrrole, through molecular engineering strategies. The main solvent can be carbonates (such as FEC, DMC) or ethers, and the alkali metal salt covers lithium, sodium, and potassium salts. It aims to solve the problem of battery stability over a wide temperature range, especially the problem of low-temperature operation, but it cannot solve the performance problem of high-voltage alkali metal batteries at high temperatures.

[0005] In alkali metal battery applications, the choice of electrolyte is crucial to battery performance. Traditional carbonate systems (such as EC / DEC), while resistant to oxidation (>4.5 V), generate an organic-dominated heterogeneous SEI on the alkali metal anode side, resulting in uneven ion flux and inducing dendrite formation. Ether electrolytes have good compatibility with the anode, but their oxidation stability is insufficient at 4.0 V, making them difficult to match with high-voltage cathodes.

[0006] Current research commonly employs molecular engineering techniques (α-H substitution or fluorination modification) to enhance the oxidation limit of ether-based electrolytes. While this has yielded some progress, the increased complexity of synthetic routes drives up manufacturing costs. Furthermore, strong electron-withdrawing strategies such as fluorination often sacrifice ionic conductivity, and their applicability to sodium metal systems still requires redesign. More importantly, electrolyte optimization is not a competition based on a single metric but must simultaneously meet multiple constraints, including cycle life, safety, and cost-effectiveness.

[0007] Therefore, in order to take into account both the advantages of intrinsic ion transport and the new paradigm of high voltage stability, and to realize the sustainable application of ether electrolytes in high-energy-density alkali metal batteries, it is urgent to develop an electrolyte containing hydrogen anion compounds and an alkali metal battery. Summary of the Invention

[0008] 1. The problem to be solved One objective of this invention is to provide an electrolyte containing hydrogen anion compounds, which aims to form double hydrogen bonds, regulate the orientation of non-aqueous organic solvents in the Helmholtz layer (IHP) within the positive and negative electrodes, and shield the active hydrogen atoms (H atoms) that are easily oxidized under high voltage. δ+ The site significantly inhibits the oxidative decomposition of non-aqueous organic solvents, thereby extending the oxidative stability of the electrolyte.

[0009] Another objective of this invention is to provide an alkali metal battery that achieves high stability at high voltage and excellent high-temperature performance.

[0010] 2. Technical Solution To solve the above problems, the technical solution adopted by the present invention is as follows: According to the purpose of this invention, a first aspect of the invention provides an electrolyte containing a hydrogen anion compound, comprising... a) Alkali metal salts; b) Non-aqueous organic solvents containing active hydrogen or oxygen atoms; c) Additives containing hydride anions that form double hydrogen bonds with non-aqueous organic solvents.

[0011] Using the above technical solution, a method for constructing an electrolyte by introducing trace amounts of hydride anion-containing compound additives through atomic engineering strategies is employed. The solvent is required to typically contain functional groups capable of providing hydrogen bond donors or acceptors (such as active hydrogen or oxygen atoms), thus possessing the potential to interact with the hydride anions in the additive. The additive is a hydride anion-containing compound, wherein the H... - Hydrogen ions (H+) can form double hydrogen bonds with active hydrogen or oxygen atoms in non-aqueous organic solvents. - These additives can form double hydrogen bonds with non-aqueous organic solvent molecules, thereby weakening the ion-dipole interaction between alkali metal cations and non-aqueous organic solvents, promoting the desolvation kinetics of alkali metal cations at the negative electrode, and improving the uniformity of alkali metal cation deposition at the negative electrode. Simultaneously, these additives, by adjusting the orientation of non-aqueous organic solvents in the Helmholtz layer (IHP) within the positive and negative electrodes, shield against easily oxidized active hydrogen atoms (H atoms) under high voltage. δ+ The invention utilizes specific sites to significantly inhibit the oxidative decomposition of non-aqueous organic solvents, thereby extending the oxidative stability of the electrolyte. This invention provides a novel atomic-level control method for electrolyte design in high-energy-density alkali metal batteries.

[0012] As one possible implementation, the additive is one or more of the general structural formulas I, II, and III. Structural formula I is MH n ; The general structural formula II is M(AH4). m ; The general structural formula III is (R)⁴N·BH⁴; where: M is Li + Na + K + Ca 2+ Ba 2+ Mg 2+ Ti 2+ Al 3+ 、Rb + Cs + 、Sr 2+ Zn 2+ ,Sc 3+ Y 3+ La 3+ Zr 4+ Hf 4+ U 4+ ; AH4 - BH4 - AlH4 - GaH4 - or InH4 - ; n is the number of H; m is AH4 - The number of; R is an alkyl group with 1 to 4 carbon atoms.

[0013] As one possible implementation, the additive includes one or more of LiH, NaH, KH, CaH2, BaH2, TiH2, MgH2, AlH3, LiBH4, NaBH4, KBH4, LiAlH4, NaAlH4, tetramethylammonium borohydride ((CH3)4N·BH4), and tetrabutylammonium tetrahydroborate.

[0014] As one possible implementation, the molar concentration of the additive in the non-aqueous organic solvent is between 0 and 0.1 mol / L, preferably 0.05 mol / L, meaning the molar concentration of the additive to the volume of the non-aqueous organic solvent is 0 to 0.1 mol / L, preferably 0.05 mol / L. Introducing trace amounts of hydrogen-containing anion compound additives into conventional electrolytes through atomic engineering strategies to form double hydrogen bonds with the organic solvent of this application can achieve performance advantages for high-voltage lithium metal batteries at high temperatures, which is one of the highlights of this application.

[0015] As one possible implementation, the non-aqueous organic solvent is one or more of the following: ether organic solvents, alcohol organic solvents, amide organic solvents, carbonate organic solvents, nitrile organic solvents, and sulfoxide organic solvents. The active hydrogen or oxygen atoms in the functional groups such as ether bonds (—O—), hydroxyl groups (—OH), amide groups (—NH—), carbonyl groups (—C=O), or cyano groups (—CN) in these solvent molecules can act as hydrogen bond donors or acceptors, forming stable double hydrogen bonds with hydride anions.

[0016] Existing technologies document single-hydrogen-bonded electrolytes; however, these electrolytes suffer from low ion transport efficiency, poor interfacial stability, and insufficient oxidation stability. For example, a single hydrogen bond is insufficient to effectively weaken the ion-dipole interaction between alkali metal ions and the solvent, leading to slow lithium-ion desolvation, easy formation of lithium dendrites, and impacting battery rate performance and safety. Simultaneously, single hydrogen bonds are easily broken under high voltage, failing to effectively shield active hydrogen atoms in the solvent, resulting in solvent oxidative decomposition and accelerated battery capacity decay. The aforementioned technical solution utilizes a double-hydrogen-bonded electrolyte, where a hydride-containing anion compound forms double hydrogen bonds with active hydrogen atoms in the solvent. This significantly enhances ion transport performance, promotes the desolvation kinetics of alkali metal ions, improves ion transport efficiency, and enhances battery rate performance. The double hydrogen bond also provides more stable shielding of active hydrogen atoms, reducing interfacial side reactions and improving interfacial stability. Furthermore, the strong binding ability of the double hydrogen bond effectively inhibits solvent oxidative decomposition, expanding the electrolyte's voltage window and allowing it to remain stable under high voltage conditions.

[0017] Therefore, double hydrogen bond electrolytes exhibit excellent performance in high energy density alkali metal batteries, overcoming the shortcomings of single hydrogen bond electrolytes.

[0018] As one possible implementation, the ether organic solvent includes straight-chain ethers and / or cyclic ethers, wherein the straight-chain ethers include, but are not limited to, one or more of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether, and the cyclic ethers include, but are not limited to, 1,3 One or more of dioxolane, 1,3-dioxane, tetrahydrofuran, and tetrahydropyran are used. It should be noted that the hydride ions in the additive can inhibit the ring-opening polymerization of cyclic ethers.

[0019] As one possible implementation, the alcoholic organic solvent includes, but is not limited to, one or more of ethanol, isopropanol, and butanol.

[0020] As one possible implementation, the amide organic solvent includes, but is not limited to, one or more of dimethylformamide and dimethylacetamide.

[0021] As one possible implementation, the carbonate organic solvent includes, but is not limited to, one or more of ethylene carbonate, propylene carbonate, and dimethyl carbonate.

[0022] As one possible implementation, the nitrile organic solvent includes, but is not limited to, one or more of acetonitrile and propionitrile.

[0023] As one possible implementation, the sulfoxide organic solvent includes, but is not limited to, dimethyl sulfoxide.

[0024] As one possible implementation, the alkali metal salt includes lithium salt, sodium salt, and potassium salt.

[0025] As one possible implementation, the lithium salt is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium hexafluoroantimonyate, lithium difluorophosphate, lithium dioxoborate, lithium difluorooxalate borate, and lithium bis(fluorosulfonyl)imide.

[0026] As one possible implementation, the sodium salt is selected from one or more of sodium hexafluorophosphate, sodium tetrafluoroborate, sodium perchlorate, sodium hexafluoroarsenate, sodium hexafluoroantimonate, sodium difluorophosphate, sodium dioxoborate, sodium difluorooxalate borate, and sodium bis(fluorosulfonyl)imide.

[0027] As one possible implementation, the potassium salt is selected from one or more of potassium hexafluorophosphate, potassium tetrafluoroborate, potassium perchlorate, potassium hexafluoroarsenate, potassium hexafluoroantimonate, potassium difluorophosphate, potassium dioxoborate, potassium difluorooxalate borate, and potassium bis(fluorosulfonyl)imide.

[0028] As one possible implementation, the molar concentration of the alkali metal salt in the non-aqueous organic solvent is 0.5~3 mol / L, preferably 1 mol / L. That is, the molar ratio of the alkali metal salt to the volume of the non-aqueous organic solvent is 0.5~3 mol / L, preferably 1 mol / L.

[0029] A second aspect of the present invention provides an alkali metal battery, comprising: a positive electrode material, a negative electrode material, a separator, and an electrolyte containing the aforementioned hydrogen anion compound.

[0030] As one possible implementation, the cathode material is selected from one or more of the following: sulfur-containing cathode materials, selenium-containing cathode materials, alkali metal cobaltates, alkali metal iron phosphates, alkali metal manganese iron phosphates, alkali metal manganates, alkali metal nickel iron manganates, Prussian blue, alkali metal nickel manganates, alkali metal nickel cobalt manganates, alkali metal nickel cobalt aluminum phosphates, alkali metal vanadium phosphates, and alkali metal fluorovanadium phosphates.

[0031] As one possible implementation, the negative electrode material is selected from lithium metal, lithium alloy, sodium metal, sodium alloy, potassium metal, or potassium alloy.

[0032] As one possible implementation, the diaphragm is selected from one or more of PP diaphragms, PE diaphragms, PP / PE / PP diaphragms, Al2O3 coated diaphragms, glass fiber diaphragms, PVDF diaphragms, PET / Al2O3 diaphragms, cellulose diaphragms, and aramid diaphragms.

[0033] 3. Beneficial effects Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In the electrolyte of the present invention, the additive can form double hydrogen bonds with anhydrous organic solvents. Taking ether solvents as an example, the α-H of the ether solvent forms a double hydrogen bond (H - ···α-H δ+ This weakens the ion-dipole interaction between alkali metal cations and ether solvents, promoting the desolvation kinetics of alkali metal cations at the negative electrode and improving the uniformity of alkali metal cation deposition. Simultaneously, these additives, by adjusting the orientation of ether solvent molecules in the Helmholtz layer (IHP) within both the positive and negative electrodes, shield the easily oxidized active hydrogen atoms (H atoms) of ethers under high voltage. δ+ This method utilizes specific sites to significantly inhibit the oxidative decomposition of ether solvents. It achieves high voltage stability without sacrificing the inherent advantages of ether electrolytes.

[0034] (2) In the electrolyte of the present invention, double hydrogen bonds are formed. There are many existing records of hydrogen-bonded electrolytes. The core mechanism of both involves hydrogen bond regulation, but the objects and targets are completely different: The mechanism of this application is the double hydrogen bond interaction: H in the metal hydride - It forms a unique "H" with the partially positively charged α-H in the solvent molecule. - ···α-H δ+ "Double hydrogen bonds. This effect effectively weakens the strong ion-dipole interaction between alkali metal ions and the solvent in alkali metal salts, thereby promoting the desolvation kinetics of alkali metal ions at the negative electrode, resulting in more uniform alkali metal deposition. Compared to film formation control, this method is more effective. At the same time, these double hydrogen bonds can regulate the orientation of solvent molecules at the positive electrode interface, shielding α-H sites in the solvent that are easily oxidized under high voltage, thus significantly improving the oxidative stability of the electrolyte and enabling it to withstand higher voltages."

[0035] Regarding the intermolecular hydrogen bond network regulation involved in existing technology (Chinese patent application number 202410452869.3), the hydrogen bond donor solvent forms hydrogen bonds with the host solvent, utilizing its electron-withdrawing effect to weaken the interaction between the host solvent and the alkali metal cation (Li). + Na + K + The coordination strength of the hydrogen bond donor (PF6) can lower the desolvation energy barrier and improve ion transport kinetics at low temperatures. On the other hand, the hydrogen bond donor can interact with anions in the electrolyte (such as PF6) to enhance coordination strength, thereby lowering the desolvation energy barrier and improving ion transport kinetics at low temperatures. - FSI - Hydrogen bonds are formed, "pulling" the anions to the solvated inner layer. This promotes the preferential decomposition of anions during the electrochemical process, which helps to form a more stable SEI / CEI film rich in inorganic fluorides on the electrode surface, thereby improving interfacial stability and inhibiting dendrite growth.

[0036] (3) Due to the different mechanisms mentioned above, the focus of performance improvement for alkali metal batteries differs: The advantages of alkali metal performance brought about by the double hydrogen bonds in this application are mainly concentrated in high voltage, high rate and high temperature environments: High voltage stability: The Li-NCM811 battery using the electrolyte of this application can retain more than 80% of its capacity after 400 cycles at a high voltage of 4.4V, which significantly expands the working window of electrolytes such as ether.

[0037] Fast charging and high temperature performance: The battery can still cycle stably at a high temperature of 60℃ and a high rate of 30C, demonstrating excellent fast charging and high temperature adaptability.

[0038] Dendrite suppression: Scanning electron microscopy (SEM) results show that the lithium metal deposition morphology is more dense and uniform after using this electrolyte, which effectively alleviates dendrite growth.

[0039] Hydrogen-bonded electrolytes, on the other hand, are only particularly effective in wide-temperature operation, especially in low-temperature performance.

[0040] (4) The electrolyte of this invention proposes a "metal hydride double hydrogen bond" mechanism, which is a precise control strategy at the atomic level. It directly solves the core problem of poor intrinsic oxidative stability of solvents from the perspective of electronic interaction. The mechanism is novel and profound. First, it is more targeted at high-voltage scenarios: its design directly targets the urgent need for high-voltage electrolytes in next-generation high-energy-density lithium metal batteries, and is more cutting-edge in improving the electrolyte voltage window.

[0041] Secondly, it directly improves the compatibility of alkali metal anodes: by promoting uniform desolvation and lithium deposition, dendrites are suppressed directly from the source, rather than from the perspective of film formation. This is of great significance for improving the safety and cycle life of lithium metal batteries as a specific system.

[0042] In summary, the electrolyte of this invention precisely improves the high-voltage stability of the electrolyte through an atomic engineering strategy (metal hydride double hydrogen bonds), which is beneficial for overcoming the high energy density bottleneck of lithium metal batteries. Attached Figure Description

[0043] Figure 1 This is a comparison chart of the cycle data of lithium-lithium symmetric batteries assembled with electrolytes prepared in Example 1 and its control group.

[0044] Figure 2 This is a comparison chart of the cycling data of lithium copper half-cells assembled with electrolytes prepared in Example 2 and its control group.

[0045] Figure 3This is a comparison chart of the cycle data of lithium-NCM811 batteries assembled with electrolytes prepared in Example 3 and its control group.

[0046] Figure 4 This is a comparison chart of cycle data for lithium copper half-cells assembled using electrolytes prepared with different concentrations of additives in Example 4.

[0047] Figure 5 This is a comparison chart showing the number of cycles in which the coulombic efficiency of lithium copper half-cells assembled with electrolytes prepared using different concentrations of additives in Example 4 was less than 90%.

[0048] Figure 6 This is a comparison chart of the high-temperature cycling data of lithium-NCM811 batteries assembled with the electrolytes configured in Example 5 and its control group.

[0049] Figure 7 This is a comparison chart of the rate performance of lithium-NCM811 batteries assembled with electrolytes prepared in Example 6 and its control group at high temperatures.

[0050] Figure 8 The image shows a scanning electron microscope (SEM) image of the copper foil after lithium deposition in the lithium-copper half-cell assembled with the electrolytes configured in Example 7 and its control group.

[0051] Figure 9 This is a comparison chart of the cycle data of lithium-LFP811 batteries assembled with electrolytes prepared in Example 8 and its control group.

[0052] Figure 10 This is a photograph illustrating how LiBH4 inhibits the ring-opening polymerization of cyclic ethers, as shown in Example 9.

[0053] Figure 11 This is a comparison chart of the cycling data of Na-NVP batteries assembled with electrolytes prepared in Example 10 and its control group.

[0054] Figure 12 This is a schematic diagram of the electrolyte action mechanism of Example 10 and its control group.

[0055] Figure 13 This is a comparison chart of the cycling data of Li-NCM811 batteries assembled with electrolytes prepared in Example 11 and its control group.

[0056] Figure 14 This is a comparison chart of the cycle data of potassium-potassium symmetric batteries assembled with electrolytes prepared in Example 12 and its control group. Detailed Implementation

[0057] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0058] Example 1 1 mmol of lithium bis(fluorosulfonyl)imide and 0.05 mmol of LiBH4 were added to 1 mL of ethylene glycol dimethyl ether and stirred until completely dissolved. A lithium-lithium symmetric battery was then assembled using this electrolyte, lithium foil, and separator, and measured at 0.5 mA·cm⁻¹. -2 1mAh·cm -2 Cyclic testing was performed at current densities, such as... Figure 1 As shown, a lithium-lithium symmetric battery using the electrolyte of the present invention can cycle stably for 1800 hours and has a small overpotential. This embodiment demonstrates that the electrolyte of the present invention exhibits excellent cycle performance and relatively stable interface stability when used in lithium batteries.

[0059] In the control group of Example 1, the electrolyte was a 1M lithium bis(fluorosulfonyl)imide solution in ethylene glycol dimethyl ether, and other battery structures and parameter settings remained unchanged.

[0060] like Figure 1 As shown, the electrolyte in the experimental group (Example 1) can improve the cycle performance of lithium-lithium symmetric batteries, thereby extending the service life of the lithium anode.

[0061] Example 2 1 mmol of lithium bis(trifluoromethanesulfonate)imide and 0.05 mmol of LiBH4 were added to 1 mL of tetrahydrofuran and stirred until completely dissolved. A lithium-copper half-cell was then assembled using this electrolyte, lithium sheet, copper sheet, and separator, and tested at 3 mA·cm⁻¹. -2 Cyclic tests were conducted at charge / discharge rates, and the coulombic efficiency was calculated based on the amount of lithium deposited and stripped in each cycle. Figure 2 As shown, the lithium copper half-cell using the electrolyte of the present invention can cycle stably for 150 cycles with a coulombic efficiency of over 90%, indicating that the electrolyte of the present invention can improve the cycle stability of lithium batteries, while the control group only has less than 30 cycles of stable deposition and stripping.

[0062] In the control group of Example 2, the electrolyte was a 1M tetrahydrofuran solution of lithium bis(trifluoromethanesulfonate)imide, and other battery structures and parameter settings remained unchanged.

[0063] like Figure 2As shown, the electrolyte in the experimental group (Example 2) can improve the cycle performance of the lithium copper half-cell, thereby extending the service life of the lithium anode.

[0064] Example 3 1 mmol of lithium difluorosulfonylimide and 0.05 mmol of TiH2 were added to 1 mL of ethylene glycol dimethyl ether. After thorough mixing, a Li-NCM811 battery was assembled using this electrolyte, lithium foil, separator, and NCM811 electrode. Cycling tests were conducted at 2C, with a charge-discharge range of 3–4.4 V. Figure 3 As shown, the control group exhibited significant capacity decay after 100 cycles, while the experimental group retained over 80% of its capacity after 400 cycles. This demonstrates that the electrolyte prepared with this solvent can effectively improve the stability of the lithium metal anode and extend the cycle life of lithium metal batteries.

[0065] In the control group of Example 3, the electrolyte was a 1M lithium bis(fluorosulfonyl)imide solution in ethylene glycol dimethyl ether, and other battery structures and parameter settings remained unchanged.

[0066] like Figure 3 As shown, the electrolyte in the experimental group (Example 3) can improve the cycle life of the NCM811 battery.

[0067] Example 4 1 mmol of lithium bis(trifluoromethanesulfonate)imide (LiTFSI) and different concentrations of lithium tetrahydroborate (LiBH4) additives were added to 1 mL of dimethyl glycol ether (DME) and stirred thoroughly until completely dissolved. Subsequently, lithium-copper half-cells were assembled using this series of electrolytes, lithium sheets, copper sheets, and separators, and measured at 3 mA·cm⁻¹. -2 Cyclic tests were conducted at a constant charge-discharge rate. The coulombic efficiency was calculated by measuring the amount of lithium deposited and stripped during each cycle. Figure 4 As shown, the additive concentrations from top to bottom are 0.01 M, 0.05 M, 0.1 M, and 0.2 M. Experimental results indicate that, as... Figure 5 As shown, when the additive concentration is 0.05 M, the lithium-copper half-cell assembled with the electrolyte can stably cycle 120 times with a coulombic efficiency maintained above 90%, indicating that 0.05 M is the optimal additive concentration for the electrolyte of this invention. When the additive concentration exceeds 0.1 M, the performance of the electrolyte decreases sharply.

[0068] Example 5 1 mmol of lithium difluorosulfonylimide and 0.05 mmol of KBH4 were added to 1 mL of ethylene glycol dimethyl ether and stirred until completely dissolved. A Li-NCM811 battery was then assembled using this electrolyte, lithium foil, separator, and NCM811 electrode. Cycling tests were conducted at 60°C and 30C, with a charge-discharge range of 3–4.4 V. Figure 5 As shown, the control group exhibited significant capacity decay after 80 cycles, while the experimental group retained over 80% of its capacity after 320 cycles. This demonstrates that the electrolyte prepared with this solvent can cycle stably at a high temperature of 30°C, further indicating that the electrolyte of this invention can achieve rapid charge and discharge at high temperatures.

[0069] In the control group of Example 5, the electrolyte was a 1M lithium bis(fluorosulfonyl)imide solution in ethylene glycol dimethyl ether, and other battery structures and parameter settings remained unchanged.

[0070] like Figure 6 As shown, the electrolyte in the experimental group (Example 5) can achieve high-temperature rapid charging and discharging.

[0071] Example 6 1 mmol of lithium bis(fluorosulfonyl)imide and 0.05 mmol of LiAlH4 were added to 1 mL of ethylene glycol dimethyl ether and stirred until completely dissolved. A Li-NCM811 battery was then assembled using this electrolyte, lithium foil, separator, and NCM811 electrode. Rate testing was conducted at 60°C and 50C. Figure 6 As shown, the lithium battery using the electrolyte of this invention exhibits a slight decrease in discharge specific capacity as the discharge rate gradually increases, but the change is not significant, and it maintains stable charge and discharge at a rate of 50C. This indicates that the lithium battery using the electrolyte of this invention has relatively stable rate performance under high temperature and high rate conditions.

[0072] In the control group of Example 6, the electrolyte was a 1M lithium bis(fluorosulfonyl)imide solution in ethylene glycol dimethyl ether, and other battery structures and parameter settings remained unchanged.

[0073] like Figure 7 As shown, the electrolyte in the experimental group (Example 6) exhibits relatively stable rate performance under high temperature and high rate conditions.

[0074] Example 7 1 mmol of lithium bis(fluorosulfonyl)imide and 0.05 mmol of KBH4 were added to 1 mL of ethylene glycol dimethyl ether and stirred until completely dissolved. A lithium-lithium symmetric battery was then assembled using this electrolyte, lithium sheet, copper sheet, and separator, and tested at 3 mA·cm⁻¹. -2 1 mAh·cm -2Lithium deposition was performed at a current density of [value missing]. The deposited lithium-copper half-cell was then disassembled, the copper foil was removed, and electron scanning was performed, such as [missing information]. Figure 7 , Figure 8 As shown, the lithium battery electrode surface using the electrolyte of the present invention exhibits a dense Li deposition morphology, indicating that the addition of the additive effectively alleviates the formation of lithium dendrites. In contrast, the control group electrode surface shows obvious dendritic Li dendrite growth.

[0075] In the control group of Example 7, the electrolyte was a 1M lithium bis(fluorosulfonyl)imide solution in ethylene glycol dimethyl ether, and other battery structures and parameter settings remained unchanged.

[0076] like Figure 8 As shown, the electrolyte in the experimental group (Example 7) can effectively alleviate the formation of lithium dendrites, thereby extending the service life of the lithium anode.

[0077] Example 8 0.2 mmol of lithium bis(fluorosulfonyl)imide and 0.02 mmol of LiBH4 were added to 1 mL of 1,3-dimethylformamide. Dioxolane, after being completely dissolved by stirring, was used as an electrolyte, along with lithium foil, separator, and LFP811 electrodes to assemble a Li-LFP811 battery. Cycling tests were then conducted at 1 C rate, with a charge-discharge range of 2.3–3.8 V. Figure 8 As shown, the control group exhibited significant capacity decay after 150 cycles, while the experimental group retained over 80% of its capacity after 270 cycles. This demonstrates that the electrolyte prepared with this solvent can effectively improve the stability of the lithium metal anode and extend the cycle life of lithium metal batteries.

[0078] In the control group of Example 8, the electrolyte was a 0.2 M lithium bis(fluorosulfonyl)imide solution in ethylene glycol dimethyl ether, and other battery structures and parameter settings remained unchanged.

[0079] like Figure 9 As shown in the experimental group (Example 8), the electrolyte of the present invention can improve the cycle life of LFP811 batteries.

[0080] Example 9 (1) Add 1 mmol of lithium hexafluorophosphate to 1 mL of 1,3 Dioxolane, after stirring for two hours, 1,3 Dioxolane undergoes a ring-opening polymerization reaction and completely solidifies, such as Figure 10 The test tube in the lower middle.

[0081] (2) Add 1 mmol of lithium hexafluorophosphate and 0.05 mmol of LiBH4 to 1 mL of 1,3 Dioxolane, after stirring, can be completely dissolved without undergoing ring-opening polymerization of cyclic ethers, such as... Figure 10 In the test tube at the top center, LiBH4 can inhibit the ring-opening polymerization reaction of cyclic ethers.

[0082] Example 10 1 mmol of sodium hexafluorophosphate and 0.05 mmol of NaBH4 were added to 1 mL of tetrahydrofuran and stirred until completely dissolved. A Na-NVP battery was then assembled using this electrolyte, sodium sheet, separator, and NVP electrode. Cyclic testing was conducted at 25 °C and 1 C rate, with a charge-discharge range of 2.2–3.8 V. Figure 10 As shown, the control group exhibited significant capacity decay after 500 cycles, while the experimental group retained over 80% of its capacity after 1000 cycles. This demonstrates that the electrolyte prepared with this solvent can cycle stably at a rate of 1 C at room temperature, further indicating that the electrolyte of this invention can achieve stable cycling at room temperature.

[0083] In the control group of Example 10, the electrolyte was a 1 M sodium hexafluorophosphate tetrahydrofuran solution, and other battery structures and parameter settings remained unchanged.

[0084] like Figure 11 As shown, the electrolyte in the experimental group (Example 10) can improve the cycle life of the NVP battery; like Figure 12 The diagram shows the principle of the battery in the experimental group (Example 10) and the control group.

[0085] Example 11 1 mmol of lithium bis(fluorosulfonyl)imide and 0.05 mmol of tetrabutylammonium tetrahydroborate ((n C4H9)4N[BH4]) was added to 1 mL of ethylene glycol dimethyl ether and stirred until completely dissolved. The electrolyte, lithium sheet, separator, and NCM811 electrode were then used to assemble a Li-NCM811 battery. Cyclic tests were conducted at 25°C and 2C, with a charge-discharge range of 3~4.4V.

[0086] In the control group of Example 11, the electrolyte was a 1M lithium bis(fluorosulfonyl)imide solution in ethylene glycol dimethyl ether, and other battery structures and parameter settings remained unchanged.

[0087] like Figure 13 As shown, the control group exhibited significant capacity decay after 80 cycles, while the experimental group retained over 80% of its capacity after 400 cycles. This demonstrates that the electrolyte prepared with this solvent can cycle stably at a 2C rate at high temperatures, further indicating that the electrolyte of this invention can achieve rapid charge-discharge at high temperatures.

[0088] Example 12 1 mmol of potassium hexafluorophosphate and 0.05 mmol of KBH4 were added to 1 mL of a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) at a volume ratio of 1:1. After complete dissolution, a potassium-potassium symmetric cell was assembled using this electrolyte, potassium sheet, and separator, and tested at 4 mA·cm⁻¹. -2 4 mAh·cm -2 Cyclic testing was conducted at a current density of [value missing].

[0089] In the control group of Example 12, the electrolyte was a mixed solvent of 1M potassium hexafluorophosphate ethylene carbonate (EC) and diethyl carbonate (DEC), and other battery structures and parameter settings remained unchanged.

[0090] like Figure 14 As shown, the potassium-potassium symmetric battery using the electrolyte from the experimental group (Example 12) can cycle stably for 500 hours with a small overpotential. This indicates that the electrolyte of Example 12 has excellent cycling performance and relatively stable interfacial stability when used in potassium batteries.

[0091] The above detailed embodiments provide a specific description of the analytical methods involved in this invention. It should be noted that the above description is only intended to help those skilled in the art better understand the methods and ideas of this invention, and is not intended to limit the scope of the invention. Without departing from the principles of this invention, those skilled in the art can make appropriate adjustments or modifications to this invention, and such adjustments and modifications should also fall within the protection scope of this invention.

Claims

1. An electrolyte containing a hydrogen anion compound, characterized in that: include a) Alkali metal salts; b) Non-aqueous organic solvents; c) Additives, including hydride compounds, that form double hydrogen bonds with non-aqueous organic solvents.

2. The electrolyte containing a hydrogen anion compound according to claim 1, characterized in that: The additive is one or more of the general structural formulas I, II, and III, or a mixture thereof. Structural formula I is MH n ; The general structural formula II is M(AH4). m ; The general structural formula III is (R)⁴N·BH⁴; where: M is Li + , Na + , K + , Ca 2+ , Ba 2+ , Mg 2+ , Ti 2+ , Al 3+ , Rb + , Cs + , Sr 2+ , Zn 2+ , Sc 3+ , Y 3+ , La 3+ , Zr 4+ , Hf 4+ , U 4+ ; AH4 - BH4 - AlH4 - GaH4 - or InH4 - ; n is the number of H; m is AH4 - The number of; R is an alkyl group with 1 to 4 carbon atoms.

3. The electrolyte containing a hydrogen anion compound according to claim 2, characterized in that: The additives include one or more of the following: LiH, NaH, KH, CaH2, BaH2, TiH2, MgH2, AlH3, LiBH4, NaBH4, KBH4, LiAlH4, NaAlH4, tetramethylammonium borohydride, and tetra-n-butylammonium borate.

4. An electrolyte containing a hydrogen anion compound according to any one of claims 1 to 3, characterized in that: The molar concentration of the additive in the non-aqueous organic solvent is between 0 and 0.1 mol / L, preferably 0.05 mol / L.

5. The electrolyte containing a hydrogen anion compound according to claim 4, characterized in that: The non-aqueous organic solvent is one or more of the following: ether organic solvents, alcohol organic solvents, amide organic solvents, carbonate organic solvents, nitrile organic solvents, and sulfoxide organic solvents.

6. The electrolyte containing a hydrogen anion compound according to claim 5, characterized in that: The ether organic solvents include straight-chain ethers and / or cyclic ethers, wherein the straight-chain ethers include, but are not limited to, one or more of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether, and the cyclic ethers include 1,3 One or more of dioxolane, 1,3-dioxane, tetrahydrofuran, and tetrahydropyran; The alcoholic organic solvents include one or more of ethanol, isopropanol, and butanol; The amide organic solvents include one or more of dimethylformamide and dimethylacetamide; The carbonate organic solvents include one or more of ethylene carbonate, propylene carbonate, and dimethyl carbonate; The nitrile organic solvents include one or more of acetonitrile and propionitrile; The sulfoxide organic solvents include dimethyl sulfoxide.

7. The electrolyte containing a hydrogen anion compound according to claim 4, characterized in that: The alkali metal salts include lithium salts, sodium salts, and potassium salts: The lithium salt is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium hexafluoroantimonyate, lithium difluorophosphate, lithium dioxoate borate, lithium difluorooxalate borate, and lithium bis(fluorosulfonyl)imide. The sodium salt is selected from one or more of sodium hexafluorophosphate, sodium tetrafluoroborate, sodium perchlorate, sodium hexafluoroarsenate, sodium hexafluoroantimonate, sodium difluorophosphate, sodium dioxoborate, sodium difluorooxalate borate, and sodium bis(fluorosulfonyl)imide. The potassium salt is selected from one or more of potassium hexafluorophosphate, potassium tetrafluoroborate, potassium perchlorate, potassium hexafluoroarsenate, potassium hexafluoroantimonate, potassium difluorophosphate, potassium dioxoborate, potassium difluorooxalate borate, and potassium bis(fluorosulfonyl)imide.

8. The electrolyte containing a hydrogen anion compound according to claim 4, characterized in that: The molar concentration of the alkali metal salt formed in the non-aqueous organic solvent is 0.5~3 mol / L, preferably 1 mol / L.

9. An alkali metal battery, characterized in that: include: Positive electrode material, negative electrode material, separator, and electrolyte of the hydrogen-containing negative ion compound as described in claims 1 to 8.

10. An alkali metal battery according to claim 9, characterized in that: The cathode material is selected from one or more of the following: sulfur-containing cathode materials, selenium-containing cathode materials, alkali metal cobaltates, alkali metal iron phosphates, alkali metal manganese iron phosphates, alkali metal manganates, alkali metal nickel iron manganates, Prussian blue, alkali metal nickel manganates, alkali metal nickel cobalt manganates, alkali metal nickel cobalt aluminum phosphates, alkali metal vanadium phosphates, and alkali metal fluorovanadium phosphates. The negative electrode material is selected from lithium metal, lithium alloy, sodium metal, sodium alloy, potassium metal, or potassium alloy; The diaphragm is selected from one or more of the following: PP diaphragm, PE diaphragm, PP / PE / PP diaphragm, Al2O3 coated diaphragm, glass fiber diaphragm, PVDF diaphragm, PET / Al2O3 diaphragm, cellulose diaphragm, and aramid diaphragm.

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