QUASI-SOLID-STATE ELECTROLYTE COMPOSITE BASED ON THREE-DIMENSIONALLY ORDERED MACROPOROUS METAL-ORGANIC FRAMEWORK MATERIALS FOR LITHIUM SECONDARY BATTERY AND METHOD FOR MANUFACTURING THE SAME

Abstract

A three-dimensionally ordered macroporous (3DOM) metal-organic framework material (MOF)-based quasi-solid-state electrolyte thin film for a safe quasi-solid-state lithium secondary battery are involved in present invention. In detail, the above quasi-solid-state electrolyte combines 3DOM-MOFs and the electrolytes like polymer and traditional liquid electrolyte. The special pore structures in 3DOM-MOFs could both fill the polymer electrolyte and liquid electrolyte with macropores and micropores, respectively. This unique structure could significantly enhance the Li.sup.+ conductivity rate through the different kinds of electrolytes in the corresponding pore structures as well as improves the battery performance. More importantly, this quasi-solid-state electrolyte is much safer than the traditional organic electrolyte. It should be easily to scale-up since the procedures are simple.

Claims

1. A quasi-solid-state electrolyte composition for a secondary Li battery comprising: (a) three-dimensionally ordered macroporous metal-organic framework materials (3DOM-MOFs); (b) a polymer electrolyte; (c) a liquid organic electrolyte; and (d) a lithium salt.

2. The quasi-solid-state electrolyte composition of claim 1, wherein weight percentages of the 3DOM-MOFs are in a range of 10%-70%, the weight percentages of the polymer electrolyte are in a range of 5%-20%, the weight percentages of the liquid organic electrolyte are in a range of 0.01%-0.1%, and the weight percentages of the said lithium salt are in a range of 5%-19.9%.

3. The quasi-solid-state electrolyte composition of claim 1, wherein the 3DOM-MOFs is selected from at least one of 3DOM-PCN-601, 3DOM-ZIF-8, 3DOM-ZIF-67, 3DOM-ZIF-68, 3DOM-ZIF-69, 3DOM-ZIF-70, 3DOM-ZIF-78, 3DOM-ZIF-81, 3DOM-ZIF-82, 3DOM-ZIF-95, 3DOM-ZIF-100, [{Fe.sub.3(μ.sub.3-O)(bdc).sub.3}.sub.4{Co.sub.2(na).sub.4(LT).sub.2}.sub.3] and JUC-1000.

4. The quasi-solid-state electrolyte composition of claim 1, wherein the polymer electrolyte is selected from at least one of Polyethylene oxide (PEO), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polyvinylidene difluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) and their derivates.

5. The quasi-solid-state electrolyte composition of claim 1, wherein the liquid organic electrolyte is selected from at least one of tetraethylene glycol dimethyl ether (TEGDME), 1,2-Dimethoxyethane (DME), Diethylene glycol dimethyl ether (DG), tetraglyme (TG), 1,3-dioxolane (DOL), Tetrahydrofuran (THF), and ethyl methanesulfonate (EMS).

6. The quasi-solid-state electrolyte composition of claim 1, wherein the lithium salt is selected from at least one of LiPF.sub.4, LiBF.sub.4, LiClO.sub.4, LiAsF.sub.6, LiBOB, LiODFB, LiCF.sub.3SO.sub.3, LiN(SO.sub.2CF.sub.3).sub.2.

7. The quasi-solid-state electrolyte composition of claim 1, wherein a type of the 3DOM-MOFs is one type or two types.

8. The quasi-solid-state electrolyte composition of claim 1, wherein a weight percentage of the 3DOM-MOFs ranges from 1.5% to 50%.

9. The quasi-solid-state electrolyte composition of claim 1, wherein the polymer electrolyte comprises pure PEO or a mixture of PEO and another different polymer.

10. The quasi-solid-state electrolyte composition of claim 1, wherein a weight percentage of the 3DOM-MOFs ranges from 5% to 10%.

11. The quasi-solid-state electrolyte composition of claim 1, wherein a type of the liquid organic electrolyte is one type or two types.

12. The quasi-solid-state electrolyte composition of claim 1, wherein a weight percentage of the liquid organic electrolyte ranges from 0.02% to 0.1%.

13. The quasi-solid-state electrolyte composition of claim 1, wherein a type of the lithium salt is more than two types.

14. The quasi-solid-state electrolyte composition of claim 1, wherein a weight percentage of the lithium salt ranges from 5% to 15%.

Description

BRIEF DESCRIPTION OF FIGURES

[0028] FIG. 1 is the SEM image of 3DOM-ZIF-67-PEO-LiPF.sub.4/LiBOB in example 1.

[0029] FIG. 2 is the SEM image of 3DOM-ZIF-67-PEO-LiPF.sub.4/LiBOB quasi-solid-state electrolyte with higher magnification in example 1.

[0030] FIG. 3 is the TEM image of 3DOM-ZIF-67-PEO-LiPF.sub.4/LiBOB quasi-solid-state electrolyte in example 2.

[0031] FIG. 4 is the SEM image of 3DOM-ZIF-67/3DOM-ZIF-8-PEO-LiPF.sub.4/LiBOB quasi-solid-state electrolyte with higher magnification in example 3.

[0032] FIG. 5 is the EIS results of quasi-solid-state electrolyte resistance in Example 1 and Comparative Example 1 and 3.

[0033] FIG. 6 is charge-discharge performance of the quasi-solid-state Li-ion battery in Example 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0034] Hereinafter, the present invention will be described batteries in more detail based on examples. Meanwhile, the present invention is not interpreted to be limited thereto.

Example 1

[0035] I. Production of Quasi-Solid-State Electrolyte

[0036] The PS/H.sub.2O solution is centrifugated with the rotation rate of 4000 r/h for 6 hours, and the top clear solution is poured out. The precipitation sample is dried at 90° C. for one night to obtain the ordered PS template. The above PS template is immersed into the cobalt nitrate/methanol solution with the concentration of 0.05 g/mL for 2 hours. Then the solution is removed and the PS template is dried at 90° C. for one night. The above sample is immersed into 2-methylimidazole/methanol solution with the concentration of 0.1 g/mL for 48 hours to obtain PS/ZIF-67 composite. It is immersed into DMF and stirs for 24 hours to remove PS to get the 3DOM-ZIF-67. Weigh 3DOM-ZIF-67, PEO 6 mg and 2 mg, respectively. Weigh LiPF.sub.4 and LiBOB 0.75 mg, 0.75 mg, respectively. The four samples are stirring well and then form a film using the preforming machine.

[0037] II. Electrochemical Characterization of the Quasi-Solid-State Electrolyte

[0038] The ion conductivity was tested at different temperatures.

[0039] III. Production of Li—S all-Solid-State Battery

[0040] Such electrolyte was then immersed in 70% S/CS.sub.2 solution at 155° C. for 6 h to obtain carbonaceous fabrics, which were mixed with carbon black (wt. 10%) and PVDF (10%) as the cathode material. Assembling it with Li metal and commercialized Celegard 2500 separator to Li—S battery. The battery performance was then tested at room temperature.

[0041] IV. Production of Li-Ion all-Solid-State Battery

[0042] The commercialized ternary cathode material of Nickel Cobalt Manganese (NCM523), graphite as the positive and negative electrode, respectively. While the obtained all-solid-state material is used as the electrolyte. The cell is assembled and tested under open air condition.

Example 2

[0043] In Example 2, the weight percentage of 3DOM-MOFs in the whole quasi-solid-state electrolyte was adjusted.

[0044] I. Production of Quasi-Solid-State Electrolyte

[0045] The PS/H.sub.2O solution is centrifugated with the rotation rate of 4000 r/h for 6 hours, and the top clear solution is poured out. The precipitation sample is dried at 90° C. for one night to obtain the ordered PS template. The above PS template is immersed into the cobalt nitrate/methanol solution with the concentration of 0.05 g/mL for 2 hours. Then the solution is removed and the PS template is dried at 90° C. for one night. The above sample is immersed into 2-methylimidazole/methanol solution with the concentration of 0.1 g/mL for 48 hours to obtain PS/ZIF-67 composite. It is immersed into DMF and stirs for 24 hours to remove PS to get the 3DOM-ZIF-67. Weigh 3DOM-ZIF-67, PEO 4.5 mg and 3.5 mg, respectively. Weigh LiPF.sub.4 and LiBOB 0.95 mg, 0.95 mg, respectively. The four samples are stirring well and then form a film using the preforming machine.

[0046] III. Electrochemical Characterization of the Quasi-Solid-State Electrolyte

[0047] The ion conductivity was tested at different temperatures.

[0048] IV. Production of Li—S all-Solid-State Battery

[0049] Such electrolyte was then immersed in 70% S/CS.sub.2 solution at 155° C. for 6 h to obtain carbonaceous fabrics, which were mixed with carbon black (wt. 10%) and PVDF (10%) as the cathode material. Assembling it with Li metal and commercialized Celegard 2500 separator to Li—S battery. The battery performance was then tested at room temperature.

[0050] V. Production of Li-Ion all-Solid-State Battery>

[0051] The commercialized ternary cathode material of Nickel Cobalt Manganese (NCM523), graphite as the positive and negative electrode, respectively. While the obtained all-solid-state material is used as the electrolyte. The cell is assembled and tested under open air condition.

Example 3

[0052] In Example 3, the kind number of MOFs in the whole quasi-solid-state electrolyte was adjusted.

[0053] I. Production of Quasi-Solid-State Electrolyte

[0054] The PS/H.sub.2O solution is centrifugated with the rotation rate of 4000 r/h for 6 hours, and the top clear solution is poured out. The precipitation sample is dried at 90° C. for one night to obtain the ordered PS template. The above PS template is immersed into the cobalt nitrate/methanol solution with the concentration of 0.05 g/mL for 2 hours. Then the solution is removed and the PS template is dried at 90° C. for one night. The above sample is immersed into 2-methylimidazole/methanol solution with the concentration of 0.1 g/mL for 48 hours to obtain PS/ZIF-67 composite. It is immersed into DMF and stirs for 24 hours to remove PS to get the 3DOM-ZIF-67. 3DOM-ZIF-8 is obtained with the similar procedures. Weigh 3DOM-ZIF-67, 3DOM-ZIF-8, PEO 4 mg, 2 mg, 2 mg, respectively. Weigh LiPF.sub.4 and LiBOB 0.75 mg, 0.75 mg, respectively. The above samples are stirring well and then form a film using the preforming machine.

[0055] II. Electrochemical Characterization of the Quasi-Solid-State Electrolyte

[0056] The ion conductivity was tested at different temperatures.

[0057] III. Production of Li—S all-Solid-State Battery

[0058] Such electrolyte was then immersed in 70% S/CS.sub.2 solution at 155° C. for 6 h to obtain carbonaceous fabrics, which were mixed with carbon black (wt. 10%) and PVDF (10%) as the cathode material. Assembling it with Li metal and commercialized Celegard 2500 separator to Li—S battery. The battery performance was then tested at room temperature.

[0059] IV. Production of Li-Ion all-Solid-State Battery

[0060] The commercialized ternary cathode material of Nickel Cobalt Manganese (NCM523), graphite as the positive and negative electrode, respectively. While the obtained all-solid-state material is used as the electrolyte. The cell is assembled and tested under open air condition.

Comparative Example 1

[0061] The quasi-solid-state electrolyte is produced in the same manner as in the Example 1 except that the 3DOM-MOFs used in the Example 1 was not used for Li—S battery.

Comparative Example 2

[0062] The quasi-solid-state electrolyte is produced in the same manner as in the Example 1 except that the 3DOM-MOFs used in the Example 1 was not used for Li-ion battery.

Comparative Example 3

[0063] The CR2032 coin cells were assembled by using sulfur composite (S and Li.sub.2S, 1:1 by mole) electrode as cathode, Celgard 2500 membrane as separator, and lithium foil as anode in Ar-filled glove box with moisture and oxygen level lower than 0.5 ppm. The electrolyte contains 1M lithium bis(trifluoromethane) sulfonamide (LiTFSI) in a binary solvent of dimethoxymethane/1,3-dioxolane (DME/DOL, 1:1 by volume) with 2 wt. % LiNO.sub.3 as additive.

[0064] FIG. 1 shows that the 3DOM-ZIF-67-PEO-LiPF.sub.4/LiBOB quasi-solid-state electrolyte in present invention was successfully obtained.

[0065] FIG. 2 shows that the pores of 3DOM-ZIF-67-PEO-LiPF.sub.4/LiBOB quasi-solid-state electrolyte in present invention are ordered and the particle size is not so uniform.

[0066] The TEM image in FIG. 3 confirms the existence of pores of 3DOM-ZIF-67-PEO-LiPF.sub.4/LiBOB. And some pores are blocked with the PEO, thus it is not so clear to see.

[0067] FIG. 4 is the 3DOM-ZIF-67/3DOM-ZIF-8-PEO-LiPF.sub.4/LiBOB quasi-solid-state electrolyte in present invention was successfully obtained.

[0068] FIG. 5 shows that the quasi-solid-state electrolyte resistance in Example 1 and Comparative Example 1 and 3 was 87Ω, 125Ω, 162Ω, respectively, indicating that the existence of 3DOM-MOFs particles is beneficial for reducing the resistance and improving the Li.sup.+ ion conductivity as the PEO crystallinity degree could be lowered by the 3DOM-MOFs.

[0069] FIG. 6 shows that the charge-discharge performance of the quasi-solid-state Li-ion battery in Example 1 still reaches 151 mAh even after 600 cycles. It should be noted that the nominal capacity of batteries is 200 mAh. And the profile is CC 0.5 C to 2.8 V 0.05 C for charging, and CC 0.5 C to 1.5 V for discharging.