A colored insulating coating composition for a lithium ion battery positive electrode sheet, a lithium ion battery positive electrode sheet, and a lithium ion battery

Abstract

The present application relates to the technical field of insulating coating material, and particularly relates to a colored insulating coating composition of a lithium ion battery positive electrode sheet. The colored insulating coating composition of the lithium ion battery positive electrode sheet comprises the following components: a filler 50% to 98%, a pigment 1% to 80%, a binder 1% to 10% and a solvent 10% to 50%; wherein the pigment is selected from any one of metal oxides, chromates, carbonates, sulfates and sulfides. The colored insulating coating composition provided by the present application has good insulating performance, stable electrochemical properties and stable chemical properties. The present application further provides a lithium ion battery positive electrode sheet, which comprises a current collector, a positive electrode active material layer and a colored insulating coating; the colored insulating coating is coated on the surface of the current collector; the positive electrode active material layer is coated on the surface of the current collector and is arranged on one side of the colored insulating coating; the colored insulating coating is spliced and connected with the positive electrode active material layer; wherein the colored insulating coating is formed by the colored insulating coating composition as described above.

Description

Technical Field

[0001] This invention relates to the field of insulating coating materials, and in particular to a colored insulating coating composition for a lithium-ion battery positive electrode, a lithium-ion battery positive electrode, and a lithium-ion battery. Background Technology

[0002] With the continuous development of lithium-ion batteries, they are widely used in mobile electronic devices, electric vehicles, and other fields, and people have increasingly higher requirements for the safety performance of lithium-ion batteries. The most common cause of safety problems such as fires or explosions in lithium-ion batteries is internal short circuits; among these, the mode that generates the most heat and is most prone to fire and explosion during a short circuit is the short circuit caused by the contact between the positive electrode foil and the negative electrode active material.

[0003] Therefore, in the design of lithium-ion batteries, an insulating coating is applied to the edge of the positive electrode active material layer on the positive electrode sheet to prevent the negative electrode active material from contacting the positive electrode current collector, thus preventing internal short circuits. Currently, the industry commonly uses ceramic materials as the insulating coating; the ceramic material is first coated on the aluminum foil, and then the positive electrode active material is coated around the edge of the ceramic material. This process requires identifying the position of the ceramic material before applying the positive electrode active material accordingly. However, the color of the ceramic material is not easily distinguishable from the color of the aluminum foil, making it difficult for ordinary sensors to identify. A CCD camera is needed to accurately identify the position of the ceramic material, which undoubtedly increases production costs significantly. These shortcomings are what those skilled in the art hope to overcome. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned defects in the prior art. The first aspect of this invention provides a colored insulating coating composition for a lithium-ion battery positive electrode sheet. The colored insulating coating composition has good insulation performance, stable electrochemical properties, and stable chemical properties.

[0005] Based on the first aspect of the present invention, the second aspect of the present invention also provides a lithium-ion battery positive electrode sheet.

[0006] Based on the second aspect of the present invention, the third aspect of the present invention also provides a lithium-ion battery.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A colored insulating coating composition for a lithium-ion battery positive electrode sheet, the colored insulating coating composition comprising the following components: 50% to 98% filler, 1% to 80% pigment, 1% to 10% binder, and 10% to 50% solvent; wherein the pigment is selected from any one of metal oxides, chromates, carbonates, sulfates, and sulfides.

[0009] Furthermore, the pigment is bismuth vanadate.

[0010] Furthermore, the colored insulating coating composition comprises the following components: 80%–90% filler, 5%–30% pigment, 3%–8% binder, and 20%–40% solvent.

[0011] Furthermore, the filler is selected from any one of aluminum oxide, boehmite, magnesium hydroxide, barium sulfate, and magnesium oxide.

[0012] Furthermore, the adhesive is selected from any one of PVDF, SBR, PAA, PAN, sodium alginate, and PTFE.

[0013] Furthermore, the solvent is selected from any one of NMP, water, acetone, isopropanol, and ethanol.

[0014] The present invention also provides a lithium-ion battery positive electrode sheet, the lithium-ion battery positive electrode sheet comprising a current collector, a positive electrode active material layer and a colored insulating coating; the colored insulating coating is coated on the surface of the current collector; the positive electrode active material layer is coated on the surface of the current collector and disposed on one side of the colored insulating coating; the colored insulating coating is spliced ​​and connected to the positive electrode active material layer;

[0015] The colored insulating coating is formed from a colored insulating coating composition of a lithium-ion battery positive electrode sheet as described above.

[0016] The present invention also provides a lithium-ion battery, the lithium-ion battery comprising a lithium-ion battery positive electrode, an electrolyte, and a separator; wherein the lithium-ion battery positive electrode comprises a lithium-ion battery positive electrode as described above.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The colored insulating coating composition provided by this invention has good insulation properties, stable electrochemical properties, and does not decompose under high voltage; it is also chemically stable and does not react with substances in the battery; and it does not dissolve in the battery electrolyte. Furthermore, the colored insulating coating in the positive electrode of the lithium-ion battery provided by this invention is easily distinguishable from the current collector color and can be identified using ordinary sensors, eliminating the need for a high-definition CCD camera. This reduces production costs and makes it suitable for mass production. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a lithium-ion battery positive electrode sheet provided by the present invention;

[0020] Figure 2These are graphs showing the cycle performance test results of the lithium-ion batteries prepared in Examples 1 to 4 of this invention;

[0021] Figure 3 This is a graph showing the discharge test results of the lithium-ion battery prepared in Example 1 of the present invention;

[0022] Figure 4 The graph shows the discharge test results of the lithium-ion battery prepared in Example 1 of this invention at different temperatures.

[0023] [Explanation of reference numerals in the attached diagram] 1. Current collector; 2. Positive electrode active material layer; 3. Colored insulating coating. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] A colored insulating coating composition for a lithium-ion battery positive electrode sheet, the colored insulating coating composition comprising the following components: 50%–98% filler, 1%–80% pigment, 1%–10% binder, and 10%–50% solvent; wherein the pigment is selected from any one of metal oxides, chromates, carbonates, sulfates, and sulfides. Preferably, the pigment is bismuth vanadate.

[0026] Further, the colored insulating coating composition comprises the following components: 80%–90% filler, 5%–30% pigment, 3%–8% binder, and 20%–40% solvent. Specifically, the content of the filler may be, but is not limited to, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, or 90%; the content of the pigment may be, but is not limited to, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, or 30%; the content of the binder may be, but is not limited to, 3%, 4%, 5%, 6%, 7%, or 8%; and the content of the solvent may be, but is not limited to, 20%, 25%, 30%, 35%, or 40%.

[0027] Further, the filler is selected from any one of aluminum oxide, boehmite, magnesium hydroxide, barium sulfate, and magnesium oxide. Preferably, the filler is aluminum oxide or boehmite.

[0028] Further, the adhesive is selected from any one of PVDF, SBR, PAA, PAN, sodium alginate, and PTFE. Preferably, the adhesive is any one of PVDF, SBR, and PAA.

[0029] Further, the solvent is selected from any one of NMP, water, acetone, isopropanol, and ethanol. Preferably, the solvent is NMP.

[0030] like Figure 1 As shown, the present invention also provides a lithium-ion battery positive electrode sheet, which includes a current collector 1, a positive electrode active material layer 2, and a colored insulating coating 3.

[0031] The colored insulating coating 3 is applied to the surface of the current collector 1; the positive electrode active material layer 2 is applied to the surface of the current collector 1; the positive electrode active material layer 2 is disposed on one side of the colored insulating coating 3. The colored insulating coating 3 and the positive electrode active material layer 2 are spliced ​​and connected; wherein, the colored insulating coating 3 is formed by a colored insulating coating composition of a lithium-ion battery positive electrode sheet as described above.

[0032] The present invention also provides a lithium-ion battery, the lithium-ion battery comprising a lithium-ion battery positive electrode, an electrolyte, and a separator; wherein the lithium-ion battery positive electrode comprises a lithium-ion battery positive electrode as described above.

[0033] The present invention will be further described in detail below with reference to specific embodiments.

[0034] Example 1

[0035] The colored insulating coating composition of a lithium-ion battery positive electrode sheet according to this embodiment includes the following components: 90% aluminum oxide, 5% bismuth vanadate, 3% PVDF, and 2% NMP.

[0036] (1) Weigh aluminum oxide powder, bismuth vanadate, PVDF and NMP according to the above proportions, add them to a container, stir evenly, and obtain component A;

[0037] (2) Take current collector 1, which is aluminum foil in this embodiment; coat component A on the aluminum foil to form colored insulating coating 3;

[0038] (3) Continue to coat the positive electrode active material layer 2 on the aluminum foil, dry it, and obtain the positive electrode sheet of lithium-ion battery;

[0039] (4) Take the lithium-ion battery positive electrode sheet, the existing lithium-ion battery negative electrode sheet, and the separator obtained above, stack them, coat them with glue, and put them into the shell; then continue to inject electrolyte, form and test capacity to obtain a lithium-ion battery.

[0040] Example 2

[0041] The colored insulating coating composition of a lithium-ion battery positive electrode sheet according to this embodiment includes the following components: 89% aluminum oxide, 6% bismuth vanadate, 3% PVDF, and 2% NMP.

[0042] (1) Weigh aluminum oxide powder, bismuth vanadate, PVDF and NMP according to the above proportions, add them to a container, stir evenly, and obtain component A;

[0043] (2) Take current collector 1, which is aluminum foil in this embodiment; coat component A on the aluminum foil to form colored insulating coating 3;

[0044] (3) Continue to coat the positive electrode active material layer 2 on the aluminum foil, dry it, and obtain the positive electrode sheet of lithium-ion battery;

[0045] (4) Take the lithium-ion battery positive electrode sheet, the existing lithium-ion battery negative electrode sheet, and the separator obtained above, stack them, coat them with glue, and put them into the shell; then continue to inject electrolyte, form and test capacity to obtain a lithium-ion battery.

[0046] Example 3

[0047] The colored insulating coating composition of a lithium-ion battery positive electrode sheet in this embodiment includes the following components: 88% aluminum oxide, 7% bismuth vanadate, 3% PVDF, and 2% NMP.

[0048] (1) Weigh aluminum oxide powder, bismuth vanadate, PVDF and NMP according to the above proportions, add them to a container, stir evenly, and obtain component A;

[0049] (2) Take current collector 1, which is aluminum foil in this embodiment; coat component A on the aluminum foil to form colored insulating coating 3;

[0050] (3) Continue to coat the positive electrode active material layer 2 on the aluminum foil, dry it, and obtain the positive electrode sheet of lithium-ion battery;

[0051] (4) Take the lithium-ion battery positive electrode sheet, the existing lithium-ion battery negative electrode sheet, and the separator obtained above, stack them, coat them with glue, and put them into the shell; then continue to inject electrolyte, form and test capacity to obtain a lithium-ion battery.

[0052] Example 4

[0053] The colored insulating coating composition of a lithium-ion battery positive electrode sheet in this embodiment includes the following components: 87% aluminum oxide, 8% bismuth vanadate, 3% PVDF, and 2% NMP.

[0054] (1) Weigh aluminum oxide powder, bismuth vanadate, PVDF and NMP according to the above proportions, add them to a container, stir evenly, and obtain component A;

[0055] (2) Take current collector 1, which is aluminum foil in this embodiment; coat component A on the aluminum foil to form colored insulating coating 3;

[0056] (3) Continue to coat the positive electrode active material layer 2 on the aluminum foil, dry it, and obtain the positive electrode sheet of lithium-ion battery;

[0057] (4) Take the lithium-ion battery positive electrode sheet, the existing lithium-ion battery negative electrode sheet, and the separator obtained above, stack them, coat them with glue, and put them into the shell; then continue to inject electrolyte, form and test capacity to obtain a lithium-ion battery.

[0058] Product performance testing

[0059] (1) The lithium-ion batteries prepared in Examples 1 to 4 were subjected to cycle performance tests. The lithium-ion batteries were placed in a constant temperature chamber at 25°C and cycled for 100 cycles. The test results are as follows: Figure 2 As shown; the test results of the lithium-ion battery prepared in Example 1 are group G; the test results of the lithium-ion battery prepared in Example 2 are group H; the test results of the lithium-ion battery prepared in Example 3 are group I; and the test results of the lithium-ion battery prepared in Example 4 are group J. Figure 2 The test results showed that the lithium-ion battery prepared in Group G, i.e. Example 1, had the best cycle performance.

[0060] (2) The lithium-ion batteries prepared in Example 1 were subjected to discharge tests at 0.2C, 0.5C, 1C, and 2C, respectively. The test results are as follows: Figure 3 As shown; the lithium-ion battery prepared in Example 1 was subjected to discharge tests at -20℃, -10℃, 0℃, 25℃, and 60℃. The test results are as follows. Figure 4 As shown.

[0061] Figure 3 , Figure 4 The test results show that the lithium-ion battery prepared in Example 1 has stable electrochemical properties, therefore, the positive electrode of the lithium-ion battery prepared in Example 1 has good insulation performance. It is evident that the colored insulating coating composition provided by this invention has good insulation performance and stable electrochemical properties; furthermore, the color of the colored insulating coating 3 and the current collector 1 in the prepared lithium-ion battery positive electrode are easily distinguishable, and can be identified by ordinary sensors. The colored insulating coating 3 can be identified without the need for a high-definition CCD camera, thus reducing production costs.

[0062] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A colored insulating coating composition for a lithium-ion battery positive electrode sheet, characterized in that, The colored insulating coating composition comprises the following components: 90% filler, 5% pigment, 3% binder, and 2% solvent; The pigment is bismuth vanadate, the solvent is NMP, the binder is PVDF, and the filler is aluminum oxide.

2. A colored insulating coating composition for a lithium-ion battery positive electrode sheet, characterized in that, The colored insulating coating composition comprises the following components: 89% filler, 6% pigment, 3% binder, and 2% solvent; The pigment is bismuth vanadate, the solvent is NMP, the binder is PVDF, and the filler is aluminum oxide.

3. A colored insulating coating composition for a lithium-ion battery positive electrode sheet, characterized in that, The colored insulating coating composition comprises the following components: 88% filler, 7% pigment, 3% binder, and 2% solvent; The pigment is bismuth vanadate, the solvent is NMP, the binder is PVDF, and the filler is aluminum oxide.

4. A colored insulating coating composition for a lithium-ion battery positive electrode sheet, characterized in that, The colored insulating coating composition comprises the following components: 87% filler, 8% pigment, 3% binder, and 2% solvent; The pigment is bismuth vanadate, the solvent is NMP, the binder is PVDF, and the filler is aluminum oxide.

5. A positive electrode sheet for a lithium-ion battery, characterized in that, The lithium-ion battery positive electrode sheet includes a current collector (1), a positive electrode active material layer (2), and a colored insulating coating (3); the colored insulating coating (3) is coated on the surface of the current collector (1); the positive electrode active material layer (2) is coated on the surface of the current collector (1) and disposed on one side of the colored insulating coating (3); the colored insulating coating (3) is spliced ​​and connected to the positive electrode active material layer (2); The colored insulating coating (3) is formed from a colored insulating coating composition of a lithium-ion battery positive electrode sheet according to any one of claims 1 to 4.

6. A lithium-ion battery, characterized in that, The lithium-ion battery includes a lithium-ion battery positive electrode, an electrolyte, and a separator; wherein the lithium-ion battery positive electrode includes a lithium-ion battery positive electrode as described in claim 5.

Images