TWI851371B - Onsite coagulation gel electrolyte and use thereof - Google Patents

Abstract

The invention discloses an onsite coagulation gel electrolyte and use thereof. The composition of the onsite coagulation gel electrolyte of the invention includes, in parts by weight, 2.5 to 4.8 parts by weight of a fluoroethylene carbonate, 0.03 to 0.6 parts by weight of a vinylene carbonate, 0.0 to 40.0 parts by weight of an ethyl acetate, 0.0 to 2.0 parts by weight of a poly(2-hydroxyethyl methacrylate), 1.5 to 5.5 parts by weight of a poly(vinylidene fluoride-co-hexafluoropropylene), 8.0 to 12.0 parts by weight of a bis(trifluoromethane)sulfonimide lithium salt, 4.0 to 6.0 parts by weight of a lithium hexafluorophosphate, 12.0 to 32.0 parts by weight of an ethylene carbonate, 10.0 to 26.0 parts by weight of a dimethyl carbonate, and 8.0 to 25.0 parts weight of a diethyl carbonate.

Description

Current site gel colloidal electrolyte and its use

The present invention relates to a colloidal electrolyte and its use, and in particular to an in situ gel colloidal electrolyte and a lithium ion battery comprising the in situ gel colloidal electrolyte and having both high safety and fast charge and discharge performance.

Lithium-ion batteries have become increasingly important energy storage devices and are widely used in mobile communication devices, electric cars, electric bicycles, aerospace and other fields. Lithium-ion batteries are usually composed of three parts: positive and negative electrodes, electrolytes and separators. As an important component of the battery, the electrolyte plays the role of ion transmission between the positive and negative electrodes. The electrolyte determines the electrochemical properties and safety performance of lithium-ion batteries. The electrolytes used in lithium-ion batteries are divided into liquid, solid and gel states.

At present, the electrolytes used in commercial lithium-ion batteries are mostly liquid electrolytes. However, there are endless accidents involving mobile phones and electric vehicles, which are caused by battery short circuits, fires, and even explosions. The cause is that the liquid electrolyte used is an extremely flammable liquid. In addition, during the rapid charge and discharge process of lithium-ion batteries, the liquid electrolyte can easily form lithium dendrites on the negative electrode surface and penetrate the separator, causing the lithium-ion battery to short-circuit and catch fire.

Solid electrolyte solutions have been proposed to solve the safety issues of traditional liquid electrolytes. However, lithium-ion batteries using solid electrolytes usually have difficulty in achieving the same electrical performance as those using liquid electrolytes, such as fast charging and discharging, battery cycle life, etc. Furthermore, solid electrolytes are difficult to assemble using the original liquid electrolyte process, which adds additional equipment costs.

In contrast, gel electrolyte reduces the amount of free solvent, reduces the risk of liquid electrolyte leakage and the possibility of combustion and explosion, and improves the safety performance of lithium-ion batteries. Gel electrolyte is more likely to be used in the original liquid electrolyte production line. As a result, many previous lithium-ion battery technologies also use polymer technology.

For related prior art, please refer to the patent announcement number I411149 of the Republic of China, which discloses a thermally activated protective film and places it in the structure of a lithium-ion battery. When the lithium-ion battery short-circuits and heats up, the thermally activated protective film begins to crosslink due to the temperature rise to prevent thermal runaway and avoid explosion hazards of the lithium-ion battery. However, the protective film disclosed in the prior art affects the lithium ion transfer rate, thereby reducing the electrical performance of the lithium-ion battery. The prior art uses an organic liquid electrolyte, which makes it difficult to ensure that the thermally activated protective film is unevenly coated, and local thermal runaway causes the lithium-ion battery to explode and catch fire. The prior art embodiment uses NMC111 with lower energy density, rather than the current mainstream high energy density positive electrode NMC622 and NMC811.

Another prior art, U.S. Patent Publication No. 20180183100, discloses an electrolyte additive that can improve the characteristics of lithium-ion batteries, especially the positive electrode film-forming characteristics and the high-resistance voltage characteristics of lithium-ion batteries, thereby improving the life and safety performance of lithium-ion batteries. However, although the prior art improves the safety of lithium-ion batteries, it has not passed any international safety standards (e.g., flame retardancy, needle puncture tests, etc.). The additives disclosed in the prior art are expensive and some are not available. The positive electrode of the embodiment of the prior art is _LiCoO2, which does not use the mainstream high-energy density positive electrode NMC622 and NMC811.

For the prior art of gel electrolyte, please refer to Chinese mainland patent publication No. 111909352, which discloses a reaction crosslinking and curing of a polyether chain segment compound monomer terminated with isocyanate on both sides of the chain segment, a polyol monomer, a reaction solvent and a catalyst, and an electrolyte is added before the reaction is completed, and the crosslinking and curing reaction continues until the reaction is completed to form a gel polymer electrolyte. However, because the prior art involves a free radical crosslinking and curing reaction, the reaction process is relatively unstable and dangerous, and it is difficult to control the crosslinking and gelling time. The fast charging performance of the lithium ion battery using the gel polymer electrolyte of the prior art is worse than that of the lithium battery using a liquid electrolyte. Although the lithium-ion battery using the gel polymer electrolyte of the prior art improves the safety of the lithium-ion battery, it has not passed any international safety standards (e.g., flame retardancy, needle puncture test, etc.).

There is also a prior art Chinese mainland patent publication number 112670567 that discloses the use of in-situ polymerization to prepare a gel solid electrolyte, so that it can be injected into a lithium-ion battery in the original liquid electrolyte mode and can improve the safety of the lithium-ion battery. However, the prior art uses an in-situ polymerization method to prepare the electrolyte, which involves a free radical reaction, so the reaction process is less stable and dangerous. Furthermore, the prior art can only use an NMC111 positive electrode for the positive electrode used in lithium-ion batteries, and the energy density of the battery cannot be improved. The lithium-ion battery using the gel solid electrolyte of the prior art has only been subjected to a flame retardant test for the safety of the lithium-ion battery, but has not passed any international acupuncture safety standards.

There is also a prior art Chinese patent publication number 114824462 that discloses a fluorinated polymer gel electrolyte formed by drying a fluorinated polymer to form a film and then soaking it in an electrolyte. This prior art requires the preparation of a fluorinated polymer film, which is difficult to apply to current commercial liquid electrolyte lithium-ion battery equipment systems. Although the lithium-ion battery using the fluorinated polymer gel electrolyte of the prior art improves the safety of the lithium-ion battery, it has not passed any international safety standards (e.g., flame retardancy, needle puncture tests, etc.).

In view of the problems pointed out in the above detailed description of the previous technology of using polymer technology in lithium-ion batteries, there is currently research on the development of electrolytes using in situ gel technology. Electrolytes using in situ gel technology have the advantages of high safety, no chemical reaction, good electrode wetting, and applicability to existing lithium-ion battery production lines. However, the fast charging and discharging performance of existing electrolytes using in situ gel technology in lithium-ion batteries still has a lot of room for improvement. Therefore, there is still a lot of room for research on the optimal composition of electrolytes using in situ gel technology.

In addition, most of the additives of the electrolyte in the prior art include lithium bis(oxalato)borate (LiBOB). LiBOB has high electrical conductivity, wide electrochemical window and good thermal stability. Its greatest advantage lies in its film-forming performance, which can directly participate in the formation of the solid electrolyte interface (SEI) film. However, LiBOB has obvious disadvantages. Its solubility in aprotic solvents is low, which leads to low conductivity of the electrolyte formed by it, thereby limiting the rate performance of the salt battery.

Therefore, one of the technical problems to be solved by the present invention is to provide a kind of in situ gel colloidal electrolyte and a lithium ion battery containing the in situ gel colloidal electrolyte that self-gelates. The in situ gel colloidal electrolyte according to the present invention does not contain LiBOB. The lithium ion battery using the in situ gel colloidal electrolyte according to the present invention has both high safety and fast charge and discharge performance.

According to a preferred embodiment of the present invention, the in situ gel electrolyte comprises 2.5 to 4.8 parts by weight of fluoroethylene carbonate (FEC), 0.03 to 0.6 parts by weight of vinylene carbonate (VC), 0.0 to 40.0 parts by weight of ethyl acetate (EA), 0.0 to 2.0 parts by weight of poly(2-hydroxyethyl methacrylate), p-HEMA, 1.5 to 5.5 parts by weight of poly(vinylidene fluoride-co-hexafluoropropylene), 8.0 to 12.0 parts by weight of bis(trifluoromethane)sulfonimide lithium salt, LiTFSI, 4.0 to 6.0 parts by weight of lithium hexafluorophosphate (LiPF ₆ ), 12.0 to 32.0 parts by weight of ethylene carbonate (EC), 10.0 to 26.0 parts by weight of dimethyl carbonate (DMC) and 8.0 to 25.0 parts by weight of diethyl carbonate (DEC). Fluorinated ethylene carbonate, vinylene carbonate, ethyl acetate, polyhydroxyethyl methyl methacrylate, polyvinylidene fluoride-hexafluoropropylene copolymer, bis(trifluoromethylsulfonyl)amide lithium, ethylene carbonate, dimethyl carbonate and diethyl carbonate are mixed and reacted to form a liquid solution. The liquid solution is allowed to stand at room temperature for at least 4 hours to gel into a solid electrolyte.

In one embodiment, ethylene carbonate, dimethyl carbonate and diethyl carbonate form a lithium salt solvent. The concentration of lithium bis(trifluoromethylsulfonyl)amide dissolved in the lithium salt solvent ranges from 0.45M to 0.55M.

In one embodiment, ethylene carbonate, dimethyl carbonate and diethyl carbonate form a lithium salt solvent. The concentration of lithium hexafluorophosphate dissolved in the lithium salt solvent ranges from 0.45M to 0.55M.

A lithium ion battery according to a preferred embodiment of the present invention comprises a positive electrode, a negative electrode, a separator and an in-situ gelled colloidal electrolyte according to the present invention. The separator is provided to separate the positive electrode from the negative electrode. Fluorinated ethylene carbonate, vinylene carbonate, ethyl acetate, polyhydroxyethyl methyl methacrylate, polyvinylidene fluoride-hexafluoropropylene copolymer, bis(trifluoromethylsulfonyl)amide lithium, ethylene carbonate, dimethyl carbonate and diethyl carbonate are mixed and reacted to produce a liquid solution. The liquid solution is injected into a first space between the positive electrode and the separator and a second space between the negative electrode and the separator. The liquid solution was allowed to stand at room temperature for at least 4 hours to gel into a solid electrolyte.

In a specific embodiment, the positive electrode can be made of LiNi _0.33 Co _0.33 Mn _0.33 O ₂ (NMC111), LiNi _0.33 Mn _0.33 Co _0.33 O ₂ (NMC333), LiNi _0.5 Mn _0.3 Co _0.2 O ₂ (NMC532), LiNi _0.6 Mn _0.2 Co _0.2 O ₂ (NMC622), LiNi _0.8 Mn _0.1 Co _0.1 O ₂ (NMC811), LiNi _0.8 Co _0.15 Al _0.05 O ₂ (NCA), LiNiO ₂ , Li _1+z Ni _x Mn _y O ₂ , Li _1+z Ni _x Mn _y Co _1-xy O ₂ , Li _1+z Ni _x Co _y Al _z O ₂ , LiV ₂ O ₅ , LiTiS ₂ , LiMoS ₂ , LiMnO ₂ , LiCoO ₂ (LCO), LiCrO ₂ , LiMn ₂ O ₄ (LMO), LiFePO ₄ (LFP) or a mixture of the above lithium metal oxides, wherein each x is independently from 0.3 to 0.8, each y is independently from 0.1 to 0.45, and each z is independently from 0 to 0.2. The above NMC532, NMC622, and NMC811 are high voltage and high nickel content ternary cathode materials.

In a specific embodiment, the negative electrode can be formed of graphite, hard carbon, soft carbon, meso-carbon micro-beads, surface-modified graphite, carbon-coated graphite, or a mixture of the above carbon materials.

Unlike the prior art, the present invention does not contain LiBOB. The present invention has the advantages of high safety, no chemical reaction, good electrode wetting, and applicability to existing lithium-ion battery production lines, and is suitable for high-voltage positive electrodes. Lithium-ion batteries using the present invention have the advantages of fast charge and discharge performance.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the attached drawings.

It should be emphasized that the present gel colloidal electrolyte according to the present invention does not contain LiBOB.

According to the preferred embodiment of the present invention, the in situ gel colloidal electrolyte comprises, by weight, 2.5 to 4.8 parts of fluoroethylene carbonate (FEC), 0.03 to 0.6 parts of vinylene carbonate (VC), 0.0 to 40.0 parts of ethyl acetate (EA), 0.0 to 2.0 parts of poly(2-hydroxyethyl methacrylate), p-HEMA, 1.5 to 5.5 parts of poly(vinylidene fluoride-co-hexafluoropropylene), 8.0 to 12.0 parts of bis(trifluoromethane)sulfonimide lithium salt, The present invention relates to a novel nanostructured carbon foam comprising: a _...

Fluorinated ethylene carbonate, vinylene carbonate, ethyl acetate, polyhydroxyethyl methyl methacrylate, polyvinylidene fluoride-hexafluoropropylene copolymer, bis(trifluoromethylsulfonyl)amide lithium, ethylene carbonate, dimethyl carbonate and diethyl carbonate are mixed and reacted to form a liquid solution. In particular, the liquid solution is allowed to stand at room temperature for at least 4 hours to gel into a solid electrolyte.

In one embodiment, ethylene carbonate, dimethyl carbonate and diethyl carbonate form a lithium salt solvent. The concentration of lithium bis(trifluoromethylsulfonyl)amide dissolved in the lithium salt solvent ranges from 0.45M to 0.55M.

In one embodiment, ethylene carbonate, dimethyl carbonate and diethyl carbonate form a lithium salt solvent. The concentration of lithium hexafluorophosphate dissolved in the lithium salt solvent ranges from 0.45M to 0.55M.

According to the preferred specific embodiment of the present invention, the in situ gelled electrolyte is an internal gelled electrolyte, and the polymers used are PVDF-HFP and p-HEMA, wherein PVDF-HFP can generate an interaction force with PF ₆ ^- in the lithium salt LiPF ₆ in the formula, effectively fix the anions, and increase the lithium ion migration capacity. In addition, the inventor of this case has verified through electron density functional theory (DFT) simulation that PVDF-HFP can effectively help the lithium salt dissociate and improve the ion conducting capacity. PHEMA (polyhydroxyethyl methacrylate) has polarized hydroxyl (OH) groups, which are hydrophilic when aggregated, and can be used to increase the interface compatibility between the electrode and the electrolyte.

The lithium ion battery according to the preferred embodiment of the present invention comprises a positive electrode, a negative electrode, a separator and an in-situ gelled colloidal electrolyte according to the present invention. The separator is provided to isolate the positive electrode from the negative electrode. Fluorinated ethylene carbonate, vinylene carbonate, ethyl acetate, polyhydroxyethyl methyl methacrylate, polyvinylidene fluoride-hexafluoropropylene copolymer, bis(trifluoromethylsulfonyl)amide lithium, ethylene carbonate, dimethyl carbonate and diethyl carbonate are mixed and reacted to produce a liquid solution. The liquid solution is injected into the first space between the positive electrode and the separator and the second space between the negative electrode and the separator. The liquid solution was allowed to stand at room temperature for at least 4 hours to gel into a solid electrolyte.

Compared to the prior art of using in-situ polymerization to prepare electrolytes, which involves free radical reactions, the in-situ gelled electrolyte of the present invention is stable and safe in that it self-condenses into a solid electrolyte, and can be applied to positive electrodes made of various alloys, including high-voltage and high-nickel-content ternary positive electrode materials. The in-situ gelled electrolyte of the present invention can be used in the original liquid electrolyte production line without increasing the manufacturing cost.

In a specific embodiment, the positive electrode can be made of LiNi _0.33 Co _0.33 Mn _0.33 O ₂ (NMC111), LiNi _0.33 Mn _0.33 Co _0.33 O ₂ (NMC333), LiNi _0.5 Mn _0.3 Co _0.2 O ₂ (NMC532), LiNi _0.6 Mn _0.2 Co _0.2 O ₂ (NMC622), LiNi _0.8 Mn _0.1 Co _0.1 O ₂ (NMC811), LiNi _0.8 Co _0.15 Al _0.05 O ₂ (NCA), LiNiO ₂ , Li _1+z Ni _x Mn _y O ₂ , Li _1+z Ni _x Mn _y Co _1-xy O ₂ , Li _1+z Ni _x Co _y Al _z O ₂ , LiV ₂ O ₅ , LiTiS ₂ , LiMoS ₂ , LiMnO ₂ , LiCoO ₂ (LCO), LiCrO ₂ , LiMn ₂ O ₄ (LMO), LiFePO ₄ (LFP) or a mixture of the above lithium metal oxides, wherein each x is independently from 0.3 to 0.8, each y is independently from 0.1 to 0.45, and each z is independently from 0 to 0.2. The above NMC532, NMC622, and NMC811 are high voltage and high nickel content ternary cathode materials.

In a specific embodiment, the negative electrode can be formed of graphite, hard carbon, soft carbon, meso-carbon micro-beads, surface-modified graphite, carbon-coated graphite, or a mixture of the above carbon materials.

The components of Example 1 and Example 2 of the in situ gel electrolyte according to the present invention are listed in Table 1. As a comparison, a commercial liquid electrolyte is used in the comparative example, and its components are also listed in Table 1.

Table 1 Example ingredients (wt.%) Embodiment 1 Embodiment 2 Comparison Example FEC 4.55 2.925 0 VC 0.43 0.0175 1.0 EA 37.1 0 0 p-HEMA 0 0.132 0 PVDF-HFP 4.55 2.258 0 LiTFSI 10.6 11.12 0 _LiPF6 5.34 5.624 12.3 EC 14.7 30.57 34.0 DMC 11.9 24.76 27.6 DEC 10.8 22.56 25.1

The electrolytes of Example 1, Example 2 and Comparative Example of the present invention are used to produce lithium ion batteries, wherein the positive electrode is formed by NMC622, a high voltage and high nickel content ternary positive electrode material, the negative electrode is formed by soft carbon and artificial graphite (soft carbon: artificial graphite = 3:7), and the separator is a separator with a three-layer structure of polypropylene (PP)/polyethylene (PE)/PP produced by Celgard. The specific capacitance of the positive electrode material is greater than 180 mAh/g. After the lithium ion batteries using the in-situ gelled electrolyte of Example 1 and Example 2 of the present invention are assembled, they are all left at room temperature for at least 4 hours to gel into a solid electrolyte. The above three lithium ion batteries all achieve the battery design goal, and their capacity is 1560 mAh.

The results of the capacitance and capacitance ratio of the lithium-ion battery using the electrolyte of Example 1, Example 2 and the comparative example of the present invention at different charge and discharge rate tests are summarized in Table 2. The charge and discharge rate tests are 0.2C/0.2C, 0.5C/0.5C, 1C/1C, 2C/2C, 3C/3C, 4C/4C and 5C/5C. It should be noted that the charge and discharge rate of 1C/1C means the charge rate is 1C and the discharge rate is 1C, and so on. The charge and discharge rate of 5C/5C is fast charge and discharge, which is the current development direction of lithium-ion batteries.

Table 2 Charge and discharge rate Example Battery characteristics 0.2C 0.5C 1C 2C 3C 4C 5C Comparison Example Capacity(mAh) 1607 1569 1525 1449 1341 1170 913 Capacitance ratio (%) 100.0 97.6 94.9 90.2 83.4 72.8 56.8 Embodiment 1 Capacity(mAh) 1604 1553 1502 1399 1298 1112 788 Capacitance ratio (%) 100.0 96.8 93.6 87.2 80.9 69.3 49.1 Embodiment 2 Capacity(mAh) 1546 1492 1434 1330 1204 977 668 Capacitance ratio (%) 100.0 96.5 92.8 86.0 77.9 63.2 43.2

The lithium-ion batteries of Example 1, Example 2 and the comparative example of the present invention have been measured, and the battery impedance of the three lithium-ion batteries is distributed between 27 and 31 mohm, wherein the impedance of the lithium-ion batteries of Example 1 and Example 2 of the present invention is higher than the impedance of the lithium-ion battery of the comparative example. Under the condition of 2C/2C charge and discharge rate, the lithium-ion batteries of Example 1 and Example 2 can have a capacity extraction of more than 86%, which is slightly lower than the capacity of the lithium-ion battery of the comparative example. It is emphasized again that the lithium-ion battery of the comparative example is a lithium-ion battery using a commercial liquid electrolyte. After different charge and discharge rate tests, the lithium ion batteries of Example 1, Example 2 and the comparative example of the present invention have no obvious expansion and thickness increase. The results listed in Table 2 confirm that the fast charge and discharge performance of the lithium ion batteries of Example 1 and Example 2 of the present invention is quite close to the fast charge and discharge performance of the lithium ion battery of the comparative example, especially the fast charge and discharge performance of the lithium ion battery of Example 1 of the present invention is closer to the fast charge and discharge performance of the lithium ion battery of the comparative example.

The lithium-ion batteries of Example 1, Example 2 and the comparative example of the present invention were subjected to a needle penetration test, and the needle penetration test complied with the test specification SAE J2464. The needle penetration test results of the lithium-ion batteries of Example 1 and Example 2 of the present invention were that the needle tip temperature was 80-90°C, and there was no explosion, combustion, or fire. The needle penetration test results of the lithium-ion battery of the comparative example were that the needle tip temperature was higher than 360°C, and combustion and fire occurred. The needle penetration test results confirmed that the lithium-ion batteries of Example 1 and Example 2 of the present invention passed the SAE J2464 test, and the lithium-ion battery of the comparative example did not pass the SAE J2464 test.

Through the detailed description of the preferred specific embodiments above, it is believed that it can be clearly understood that the existing gelled colloidal electrolyte according to the present invention does not contain LiBOB. The existing gelled colloidal electrolyte according to the present invention has the advantages of high safety, no chemical reaction, good electrode wetting, and applicability to existing lithium-ion battery production lines, and is suitable for high-voltage positive electrodes. The lithium-ion battery using the existing gelled colloidal electrolyte according to the present invention has the advantages of fast charging and discharging performance.

The above detailed description of the preferred specific embodiments is intended to more clearly describe the features and spirit of the present invention, but is not intended to limit the scope of the present invention to the preferred specific embodiments disclosed above. On the contrary, the purpose is to cover various changes and arrangements with equivalents within the scope of the patent application for the present invention. Therefore, the scope of the patent application for the present invention should be interpreted in the broadest sense based on the above description, so as to cover all possible changes and arrangements with equivalents.

without

without.

Claims (6)

A gel electrolyte comprises, by weight, 2.5 to 4.8 parts of fluoroethylene carbonate (FEC); 0.03 to 0.6 parts of vinylene carbonate (VC); 0.0 to 40.0 parts of ethyl acetate (EA); 0.0 to 2.0 parts of poly(2-hydroxyethyl methacrylate), p-HEMA; 1.5 to 5.5 parts of poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP; 8.0 to 12.0 parts of bis(trifluoromethane)sulfonimide lithium salt (LiTFSI); 4.0 to 6.0 parts of lithium hexafluorophosphate (LiPF4). hexafluorophosphate, LiPF ₆ ); 12.0 to 32.0 parts by weight of ethylene carbonate (EC); 10.0 to 26.0 parts by weight of dimethyl carbonate (DMC); and 8.0 to 25.0 parts by weight of diethyl carbonate (DMC). carbonate, DEC), wherein the fluoroethylene carbonate, the vinylene carbonate, the ethyl acetate, the polyhydroxyethyl methyl methacrylate, the polyvinylidene fluoride-hexafluoropropylene copolymer, the bis(trifluoromethylsulfonyl)amide lithium, the ethylene carbonate, the dimethyl carbonate and the diethyl carbonate are mixed and a synthesis reaction is generated to form a liquid solution, the liquid solution is allowed to stand at a room temperature for at least 4 hours to gel into a solid electrolyte, the gelled electrolyte is executed into a lithium ion battery, and under a charge and discharge rate of 2C/2C, the lithium ion battery has a capacity extraction of more than 86%. The in-situ gel colloidal electrolyte as described in claim 1, wherein the ethylene carbonate, the dimethyl carbonate and the diethyl carbonate form a lithium salt solvent, and the bis(trifluoromethylsulfonyl)amide lithium is dissolved in the lithium salt solvent at a concentration ranging from 0.45M to 0.55M. The in-situ gel colloidal electrolyte as described in claim 1, wherein the ethylene carbonate, the dimethyl carbonate and the diethyl carbonate form a lithium salt solvent, and the lithium hexafluorophosphate is dissolved in the lithium salt solvent at a concentration ranging from 0.45M to 0.55M. A lithium ion battery comprises: a positive electrode; a negative electrode; a separator configured to separate the positive electrode from the negative electrode; and an in-situ gel colloidal electrolyte as described in any one of claims 1 to 3, wherein the fluoroethylene carbonate, the vinylene carbonate, the ethyl acetate, the polyhydroxyethyl methyl methacrylate, the polyvinylidene fluoride-hexafluoropropylene copolymer, the bis(trifluoromethylsulfonyl)amide lithium, the ethylene carbonate, The dimethyl carbonate and the diethyl carbonate are mixed and a synthesis reaction is generated to form a liquid solution, which is injected into a first space between the positive electrode and the isolation membrane and a second space between the negative electrode and the isolation membrane. The liquid solution is left at room temperature for at least 4 hours to gel into a solid electrolyte. Under a charge and discharge rate of 2C/2C, the lithium-ion battery has a capacity extraction of more than 86%. The lithium ion battery as described in claim 4, wherein the positive electrode is selected from LiNi _0.33 Co _0.33 Mn _0.33 O ₂ (NMC111), LiNi _0.33 Mn _0.33 Co _0.33 O ₂ (NMC333), LiNi _0.5 Mn _0.3 Co _0.2 O ₂ (NMC532), LiNi _0.6 Mn _0.2 Co _0.2 O ₂ (NMC622), LiNi _0.8 Mn _0.1 Co _0.1 O ₂ (NMC811), LiNi _0.8 Co _0.15 Al _0.05 O ₂ (NCA), LiNiO ₂ , Li _1+z Ni _x Mn _y O ₂ , Li _1+z Ni _x Mn _y Co _1-xy O ₂ , Li _1+z Ni _x Co _y Al _z O ₂ , LiV ₂ O ₅ , LiTiS ₂ , LiMoS ₂ , LiMnO ₂ , LiCoO ₂ (LCO), LiCrO ₂ , LiMn ₂ O ₄ (LMO), LiFePO ₄ (LFP) and a mixture of the foregoing lithium metal oxides, each x is independently from 0.3 to 0.8, each y is independently from 0.1 to 0.45, and each z is independently from 0 to 0.2. A lithium-ion battery as described in claim 5, wherein the negative electrode is formed of one selected from the group consisting of graphite, hard carbon, soft carbon, mesophase carbon microspheres, surface-modified graphite, carbon-coated graphite, and a mixture of the above carbon materials.