CN216133880U

CN216133880U - Insulating frame and lithium metal battery comprising same

Info

Publication number: CN216133880U
Application number: CN202122081929.XU
Authority: CN
Inventors: 黄成�; 徐雄文; 王志斌; 袁依婷; 颜亚平
Original assignee: Hunan Lifang New Energy Science and Technology Co Ltd
Current assignee: Hunan Lifang New Energy Science and Technology Co Ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2022-03-25
Anticipated expiration: 2031-08-31

Abstract

The utility model belongs to the technical field of battery accessories, and particularly relates to an insulating frame and a lithium metal battery comprising the insulating frame. The insulating frame can provide supporting force for the pole pieces which are stacked, and the edge collapse of the pole pieces is avoided, so that the short circuit caused by the contact of the edges of the positive pole and the negative pole is avoided, the safety is improved, and the detection is convenient.

Description

Insulating frame and lithium metal battery comprising same

Technical Field

The utility model belongs to the technical field of battery spare and accessory parts, and particularly relates to an insulating frame and a lithium metal battery comprising the insulating frame.

Background

With the new concept and new requirements of "carbon peak-reaching" and "carbon neutralization", new opportunities and challenges are brought to the current lithium battery industry. Through years of development of traditional lithium metal batteries composed of an insertion layer type cathode/anode (such as graphite/lithium cobaltate), the energy density of the lithium metal batteries is approaching the theoretical limit, and the requirements of rapid development of mobile electronic equipment, new energy automobiles and distributed energy storage systems and related battery energy density development in '2025 of China manufacturing' are difficult to meet.

As an ancient lithium source type negative electrode material, the metal lithium attracts people again due to the extremely high theoretical specific capacity and the low oxidation-reduction potential after leaving the visual field of people for years. As is well known, the practical application of lithium metal negative electrodes is seriously hindered by the problems of lithium dendrite generation, lithium death, volume change and the like of the lithium metal negative electrodes during the battery cycling process, and researchers have adopted various strategies to relieve the problems. However, in the process of putting lithium metal batteries into practical use, the problems of the lithium metal battery preparation process due to the physicochemical properties of the metallic lithium simple substance are not inconsiderable.

The lithium metal density is only 0.534g/cm³The anode has great advantages in mass energy density when used as a cathode. However, due to low density, the lithium metal battery is easy to penetrate by X-rays, and the extension (overlap) and alignment between the positive electrode and the negative electrode of the lithium metal battery dry cell are difficult to detect by X-ray in the battery manufacturing process, so that the quality judgment of the lithium metal battery structure is influenced. In addition, the battery has soft texture, is easy to deform and adhere, and is easy to cause the edge collapse of the battery to cause poor appearance. In particular, in the preparation of all solid-state lithium metal batteries, lithium metal edges due to the lack of barrier of the separatorIs easy to be contacted with the edge of the anode by external pressure to cause short circuit.

SUMMERY OF THE UTILITY MODEL

The utility model aims to: the insulating frame is provided for overcoming the defects in the prior art, can provide supporting force for the pole pieces placed in a stacked mode, and avoids the edge collapse of the pole pieces, so that short circuit caused by contact of the edges of the positive pole and the negative pole is avoided, safety is improved, and meanwhile detection is facilitated.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the utility model provides an insulating frame, is including being used for the cover to locate the insulating frame on pole piece outside limit, insulating frame is provided with and is used for the utmost point ear of pole piece stretches out dodges the mouth.

As an improvement of the insulating frame, the insulating frame comprises a first edge strip, a second edge strip, a third edge strip and a fourth edge strip which are sequentially connected end to end, and the first edge strip is provided with an avoidance opening.

As an improvement of the insulating frame, the thickness of the insulating frame is the same as that of the pole piece.

As an improvement of the insulating frame, the outer part of the insulating frame is flat.

Another object of the present invention is to: aiming at the defects of the prior art, the lithium metal battery is provided, the problems of poor appearance and short circuit caused by the collapse of the battery edge are effectively avoided, and the safety is good.

the utility model provides a lithium metal battery, includes positive plate, negative pole piece and insulating frame, the negative pole piece with the positive plate stacks gradually and places, insulating frame cover is established the positive plate, insulating frame with the common vertical projection area of positive plate with the vertical projection area of negative plate is the same, insulating frame is foretell insulating frame.

As an improvement of the lithium metal battery of the present invention, the positive plate includes a positive current collector and a solid electrolyte layer disposed on at least one side of the positive current collector, and the thickness of the insulating frame is equal to the sum of the thickness of the positive current collector and the thickness of the solid electrolyte layer.

As an improvement of a lithium metal battery of the present invention, the positive plate includes a positive current collector, an active material layer, and a solid electrolyte layer, the active material layer is disposed on at least one side of the positive current collector, the solid electrolyte layer is disposed on a side of the active material layer away from the positive current collector and/or on a side of the positive current collector away from the active material layer, and a thickness of the insulating frame is equal to a sum of a thickness of the positive current collector, a thickness of the active material layer, and a thickness of the solid electrolyte layer.

As an improvement of a lithium metal battery of the present invention, the lithium metal battery further includes a solid electrolyte membrane for separating the positive electrode tab and the negative electrode tab.

As an improvement of the lithium metal battery of the present invention, the lithium metal battery further includes a separation film, an electrolyte, and a case, the separation film is used for separating the positive plate from the negative plate, and the case is used for mounting the positive plate, the negative plate, the separation film, and the electrolyte.

Compared with the prior art, the utility model has the beneficial effects that: the utility model provides an insulating frame which can provide supporting force for pole pieces placed in a stacked mode and avoid edge collapse of the pole pieces, so that short circuit caused by contact of edges of positive and negative poles is avoided, safety is improved, and detection is facilitated. The lithium metal battery provided by the utility model can effectively avoid the problems of poor appearance and short circuit caused by collapse of the battery edge, and has good safety.

Drawings

Fig. 1 is a schematic structural view of an insulating frame according to the present invention.

Fig. 2 is a side view of the insulating frame of the present invention.

Fig. 3 is a schematic view of the assembly of the insulating frame and the pole piece of the present invention.

Fig. 4 is a schematic structural view of a lithium metal battery according to the present invention.

Fig. 5 is a cross-sectional view taken at a-a in fig. 4.

Fig. 6 is a second schematic structural view of a lithium metal battery according to the present invention.

Fig. 7 is a sectional view taken at B-B in fig. 6.

Fig. 8 is a third schematic structural view of a lithium metal battery according to the present invention.

Fig. 9 is a sectional view at C-C in fig. 8.

Wherein: 1. an insulating frame; 2. avoiding the mouth; 3. a positive plate; 31. a positive current collector; 32. an active material layer; 33. a solid electrolyte layer; 34. a tab; 4. a negative plate; 5. a solid electrolyte membrane; 6. an isolation film; 7. a lithium metal battery.

Detailed Description

As used in the specification and in the claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, within which a person skilled in the art can solve the technical problem to substantially achieve the technical result.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", horizontal ", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The present invention will be described in further detail below with reference to the accompanying drawings, but the present invention is not limited thereto.

As shown in fig. 1 to 3, an insulation frame 1 according to the present invention includes an insulation frame for sleeving an outer side of a pole piece, and the insulation frame is provided with an avoidance opening 2 for allowing a tab 34 of the pole piece to extend out. The insulating frame 1 is sleeved on the outer side edge of the pole piece and can play a supporting role when being stacked with another pole piece, so that the short circuit caused by the contact of a positive pole and a negative pole is avoided. The arrangement of the avoiding port 2 can enable the pole lugs 34 on the pole pieces to horizontally extend out, the pole lugs 34 cannot be damaged, and the pole pieces can be conveniently stacked. The utility model provides an insulating frame 1 which can provide supporting force for pole pieces placed in a stacked mode and avoid edge collapse of the pole pieces, so that short circuit caused by contact of edges of positive and negative poles is avoided, safety is improved, and detection is facilitated.

The insulating frame 1 can be customized according to the size of the pole piece, the relative positions of the positive pole piece and the negative pole piece 4 are conveniently fixed on the premise of not reducing the volume energy density and reducing the weight energy density as little as possible, the extension (overlap) and the alignment between the positive pole piece and the negative pole piece are ensured, the process difficulty is reduced, and the quality yield is improved. When the insulating frame 1 is mounted on the positive electrode plate 3, the insulating frame 1 is used as the support of the lithium negative electrode, so that the collapse condition of the peripheral edge extending (overlapping) area of the lithium metal battery 7 is greatly improved, and the appearance is effectively improved. Particularly, in the full solid-state lithium metal battery 7 without the diaphragm, the existence of the insulating frame 1 avoids the contact of the positive and negative pole pieces 4 at the edges, and reduces the short circuit in the process. In addition, the method is simple and easy to implement, does not greatly change the existing process, and is suitable for large-scale production.

The material of the insulating frame 1 of the present invention should be an insulating material having electrochemical inertness that does not react with the electrolyte, and may be, for example, an insulating polymer material, an insulating glass material, an insulating ceramic material, an insulating glass fiber material, or any combination of the above materials. The material of the structure can be any material completely covered with the above material or any material completely covered with the above material besides the above insulating material. The insulating frame 1 has a flat outer part and a hole or no hole in the inner part.

As shown in fig. 1 to 3, the insulating frame of the present invention includes a first edge strip, a second edge strip, a third edge strip and a fourth edge strip, which are sequentially connected end to end, wherein the first edge strip is provided with an avoidance opening 2. Preferably, the insulation frame 1 is a rectangle as a whole and comprises four surrounding side strips, the four side strips form a rectangle in sequence from the first side to the last side, and meanwhile, the avoidance port 2 is arranged at the first side strip, so that the tab 34 of the pole piece can horizontally extend out conveniently, and the tab 34 is prevented from being bent and damaged.

As shown in fig. 5, 7 and 9, the thickness of the insulating frame of the present invention is the same as the thickness of the pole piece, so that the plane of the pole piece forms a horizontal platform, thereby providing a stable, overall and firm support for the other pole piece stacked on the pole piece, preventing the supported pole piece from sinking or collapsing, and further preventing the anode and the cathode from contacting and short-circuiting.

The insulating frame is smooth in outer part, and can provide smooth support for the other pole piece, so that the pole piece is prevented from being deformed.

As shown in fig. 4 to 9, the lithium metal battery 7 of the present invention includes a positive plate 3, a negative plate 4, and an insulating frame 1, wherein the negative plate 4 and the positive plate 3 are sequentially stacked, the positive plate 3 is sleeved with the insulating frame 1, a common vertical projection area of the insulating frame 1 and the positive plate 3 is the same as a vertical projection area of the negative plate 4, and the insulating frame 1 is the insulating frame 1. The outside limit of positive plate 3 is located to insulating frame 1 cover, and

positive plate

3 and 4 range upon range of placements of negative pole piece, and insulating frame 1 is located the edge of positive plate 3 to for the edge of negative pole piece 4 provides the support, thereby avoid the edge of negative pole piece 4 to sink, avoid positive negative pole contact short circuit. The lithium metal battery 7 provided by the utility model can effectively avoid the problems of poor appearance and short circuit caused by the collapse of the battery edge, and has good safety.

The positive plate 3 of the utility model comprises a positive current collector 31 and a solid electrolyte layer 33 arranged on at least one side surface of the current collector, and the thickness of the insulating frame 1 is equal to the sum of the thickness of the current collector and the thickness of the solid electrolyte layer 33. The battery is a lithium metal battery 7 with a solid electrolyte layer 33, the solid electrolyte layer 33 is arranged on two side surfaces of a positive current collector 31, a positive plate 3 and a negative plate 4 are sequentially stacked, the solid electrolyte layer 33 separates the positive current collector 31 from the negative plate 4, and meanwhile, the thickness of the insulating frame 1 is the same as that of the positive plate 3, so that the flat support can be provided for the negative plate 4, and the bending deformation of the negative plate 4 is avoided. Preferably, the solid electrolyte layer 33 employs a ceramic solid electrolyte layer 33. Wherein the active material area on the positive plate 3 is uniformly coated with a layer of ceramic solid electrolyte lithium titanium aluminum phosphate (Li) with the thickness of 0.01-0.05mm_1.4Al_0.4Ti_1.6(PO₄)₃). Preferably, the thickness of the solid electrolyte layer 33 is 0.01 mm. The insulating frame 1 is 54.5mm long outside and 45mm wide, 51.5mm long inside and 42mm wide, and 0.12mm thick, and the thickness here equals to the thickness of the positive plate 3 plus the thickness of the solid electrolyte, and the frame is 1.5mm wide and has equal width all around, is made of epoxy resin, and has no holes inside and smooth surface. An insulating frame 1 and a positive plate 3 coated with solid electrolyte are nested to form a whole, and are alternately laminated with a lithium negative electrode in a dry environment (the dew point does not exceed minus 40 ℃) to obtain a naked battery cell; and (3) placing the bare cell into an external package, and completing the preparation of the lithium metal battery 7 through packaging, formation, hot-cold pressing and capacity grading.

As shown in fig. 6 and 7, the positive electrode sheet 3 of the present invention includes a positive electrode collector 31, an active material layer 32, and a solid electrolyte layer 33, wherein the active material layer 32 is disposed on at least one side of the positive electrode collector 31, the solid electrolyte layer 33 is disposed on a side of the active material layer 32 away from the positive electrode collector 31 and/or on a side of the positive electrode collector 31 away from the active material layer 32, and a thickness of the insulating frame 1 is equal to a sum of a thickness of the collector and a thickness of the active material layer 32 and a thickness of the solid electrolyte layer 33. The positive electrode sheet 3 of the present embodiment includes a positive electrode collector 31, an active material layer 32, and a solid electrolyte layer 33, the active material layer 32 can improve the conductivity between the solid electrolyte layer 33 and the positive electrode collector 31, and the solid electrolyte layer 33 can store an electrolyte, and can effectively improve the safety performance and energy density of the battery compared to the use of a liquid electrolyte. Preferably, the active material layer 32 is disposed on both sides of the positive electrode collector 31, and the solid electrolyte layer 33 is disposed on both sides of the active material layer 32 away from the positive electrode collector 31. The positive active material comprises at least one of lithium cobaltate, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganate, a nickel manganese binary material, lithium nickel cobalt aluminate, a lithium-rich phase positive material, a polyanion positive material, an organic positive material, an inorganic sulfur material and an organic sulfur material. The negative electrode is a pure lithium negative electrode or a lithium alloy.

As shown in fig. 8 and 9, the lithium metal battery 7 of the present invention further includes a solid electrolyte membrane 5, and the solid electrolyte membrane 5 serves to separate the positive electrode tab 3 and the negative electrode tab 4. The polymer solid electrolyte is a polyethylene oxide (PEO) film containing a lithium salt and an inorganic filler. Sequentially stacking the polymer solid electrolyte membrane 5 between the anode and the cathode in a dry environment (the dew point does not exceed minus 40 ℃) to obtain a naked cell; and (3) placing the bare cell into an external package, and completing the preparation of the lithium metal battery 7 through packaging, formation, hot-cold pressing and capacity grading. The solid electrolyte membrane 5 includes an inorganic solid electrolyte, a polymer solid electrolyte, and a composite solid electrolyte. The inorganic solid electrolyte comprises perovskite type solid electrolyte, NASICON type solid electrolyte, garnet type solid electrolyte, sulfide solid electrolyte and inorganic solid electrolyte optimized by various modified doping. The polymer solid electrolyte includes polyethylene oxide (PEO) -based ones, Polyacrylonitrile (PAN) -based ones, polymethyl methacrylate (PMMA) -based ones, polyvinylidene fluoride (PVDF) -based ones, and other polymer solid electrolytes. The composite solid electrolyte is an inorganic-polymer composite solid electrolyte in various composite modes. The positive active material comprises at least one of lithium cobaltate, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganate, a nickel manganese binary material, lithium nickel cobalt aluminate, a lithium-rich phase positive material, a polyanion positive material, an organic positive material, an inorganic sulfur material and an organic sulfur material. The negative electrode is a pure lithium negative electrode or a lithium alloy. The positive plate 3 comprises a positive current collector and a positive active material layer arranged on at least one side of the positive current collector 31, and the negative plate 4 comprises a negative current collector and a negative active layer arranged on at least one side of the negative current collector.

As shown in fig. 4 and 5, the lithium metal battery 7 of the present invention further includes a separator 6, an electrolyte, and a case, wherein the separator 6 is used to separate the positive electrode tab 3 and the negative electrode tab 4. The positive electrode sheet 3 (including the positive electrode current collector 31 and the positive electrode active material distributed on the positive electrode current collector 31, the positive electrode active material being lithium cobaltate, and being baked) has a length of 51.5mm, a width of 42mm and a thickness of 0.11 mm. The negative electrode is pure lithium, 54.5mm long, 45mm wide and 0.05mm thick. Preferably, the positive electrode active material is disposed on both sides of the positive electrode current collector 31, the insulating frame 1 has an outer length of 54.5mm and a width of 45mm, an inner length of 51.5mm and a width of 42mm, a thickness of 0.11mm and a frame width of 1.5mm, and has a uniform width around the insulating frame, is made of epoxy resin, and has an inner void-free and flat surface. An insulating frame 1 and a positive plate 3 are nested to form a whole, so that an isolating membrane 6 is positioned between a positive electrode and a negative electrode, and the insulating frame and the positive plate are sequentially stacked under a dry environment (the dew point does not exceed minus 40 ℃) to obtain a naked electric core; and (3) putting the bare cell into an external package, injecting electrolyte, packaging, standing, forming, hot-cold pressing and grading to finish the preparation of the battery. The positive active material comprises at least one of lithium cobaltate, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganate, a nickel manganese binary material, lithium nickel cobalt aluminate, a lithium-rich phase positive material, a polyanion positive material, an organic positive material, an inorganic sulfur material and an organic sulfur material. The negative electrode is a pure lithium negative electrode or a lithium alloy. The positive plate 3 comprises a positive current collector and a positive active material layer arranged on at least one side of the positive current collector 31, and the negative plate 4 comprises a negative current collector and a negative active layer arranged on at least one side of the negative current collector.

While the foregoing description shows and describes several preferred embodiments of the utility model, it is to be understood, as noted above, that the utility model is not limited to the forms disclosed herein, but is not intended to be exhaustive or to exclude other embodiments and may be used in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as expressed herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the utility model as defined by the appended claims.

Claims

1. The utility model provides an insulating frame, its characterized in that, is including being used for the cover to locate the insulating frame on pole piece outside limit, insulating frame is provided with and is used for the utmost point ear of pole piece stretches out dodges the mouth.

2. The insulation frame according to claim 1, wherein the insulation frame comprises a first side strip, a second side strip, a third side strip and a fourth side strip which are sequentially connected end to end, and the first side strip is provided with an avoidance port.

3. The insulating frame of claim 1, wherein the thickness of the insulating bezel is the same as the thickness of the pole piece.

4. The insulating frame of claim 1, wherein the insulating border is flat on the outside.

5. A lithium metal battery is characterized by comprising a positive plate, a negative plate and an insulating frame, wherein the negative plate and the positive plate are sequentially stacked, the positive plate is sleeved with the insulating frame, the common vertical projection area of the insulating frame and the positive plate is the same as that of the negative plate, and the insulating frame is according to any one of claims 1-4.

6. The lithium metal battery of claim 5, wherein the positive plate comprises a positive current collector and a solid electrolyte layer disposed on at least one side of the positive current collector, and the thickness of the insulating frame is equal to the sum of the thickness of the positive current collector and the thickness of the solid electrolyte layer.

7. The lithium metal battery according to claim 5, wherein the positive electrode sheet comprises a positive electrode current collector, an active material layer and a solid electrolyte layer, the active material layer is disposed on at least one side of the positive electrode current collector, the solid electrolyte layer is disposed on a side of the active material layer away from the positive electrode current collector and/or on a side of the positive electrode current collector away from the active material layer, and the thickness of the insulating frame is equal to the sum of the thickness of the positive electrode current collector and the thickness of the active material layer and the thickness of the solid electrolyte layer.

8. The lithium metal battery according to claim 5, further comprising a solid electrolyte membrane for separating the positive electrode tab and the negative electrode tab.

9. The lithium metal battery of claim 5, further comprising a separator for separating the positive electrode tab from the negative electrode tab, an electrolyte, and a case for housing the positive electrode tab, the negative electrode tab, the separator, and the electrolyte.