阅读说明：本技术 一种膨胀芯骨的使用方法 (Application method of expansion core rod ) 是由 张广忠 王炜娜 李会娟 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种膨胀芯骨的使用方法,属于蓄电池技术领域,其特征在于,所述膨胀芯骨包括：由弹性材料制成的外套管；在所述外套管的外壁开设有一条从一端到另外一端的断裂缝；由刚性材料制成的内套管；其中：所述外套管的内径小于内套管的外径；所述使用方法包括：S1、将外套管插入极组的中心孔；S2、将内套管插入外套管中。通过采用上述技术方案,本发明使用可膨胀的芯骨,降低了极组向内膨胀空间起到更好的支撑作用,减少了电池循环过程中因极片变形导致极片褶皱,进而减少电池析锂、产气、极片粉化、掉料、断裂等一系列连锁反应。(The invention discloses a using method of an expansion core bar, belonging to the technical field of storage batteries, and characterized in that the expansion core bar comprises: an outer sleeve made of an elastic material; the outer wall of the outer sleeve is provided with a fracture seam from one end to the other end; an inner sleeve made of a rigid material; wherein: the inner diameter of the outer sleeve is smaller than the outer diameter of the inner sleeve; the using method comprises the following steps: s1, inserting the outer sleeve into the central hole of the pole group; and S2, inserting the inner sleeve into the outer sleeve. By adopting the technical scheme, the expandable core is used, so that the inward expansion space of the pole group is reduced to play a better supporting role, the pole piece wrinkles caused by pole piece deformation in the battery circulation process are reduced, and a series of chain reactions of lithium precipitation, gas generation, pole piece pulverization, material falling, fracture and the like of the battery are further reduced.)

1. A method of using an expanded core comprising:

an outer sleeve made of an elastic material; the outer wall of the outer sleeve is provided with a fracture seam from one end to the other end;

an inner sleeve made of a rigid material; wherein:

the inner diameter of the outer sleeve is smaller than the outer diameter of the inner sleeve;

the using method comprises the following steps:

s1, inserting the outer sleeve into the central hole of the pole group;

and S2, inserting the inner sleeve into the outer sleeve.

2. The method of using the expanded core according to claim 1, wherein the fracture seam is a straight seam parallel to the central axis of the outer cannula.

3. The method of using the expanded core according to claim 1, wherein the outer sleeve is a plastic sleeve.

4. The method of using the expanded core according to claim 1, wherein the inner casing is a stainless steel tube.

5. The method for using the expansion core according to claim 1, wherein one end of the outer sleeve is a conical head and the other end is a flat head.

6. The method of using an expanded core as claimed in claim 1, wherein said inner sleeve is tapered at least one end.

Technical Field

The invention belongs to the technical field of storage batteries, and particularly relates to a using method of an expansion core rod.

Background

As is known, in a lithium ion battery, along with charge and discharge cycles, positive and negative electrode plates are always in an expansion and contraction state (mainly, thickness change is caused by lithium loss due to lithium intercalation in the charge and discharge processes of the negative electrode plates), and the electrode plates become brittle, fall off materials and even break due to the influence of factors such as increased electrolyte consumption, aggravated side reactions, increased internal pressure and the like along with the increase of cycle times of the lithium ion battery. Especially, the pole pieces in the pole group of the cylindrical winding battery are extruded inwards due to the central hole in the pole group, and the internal extrusion deformation of the pole group is intensified along with the circulation, so that the internal lithium precipitation pole pieces are broken, and the potential safety hazard even occurs to the serious battery cycle water-jumping person.

In order to solve the problem of circular water-jumping caused by the deformation of the pole group in the later cycle period of the cylindrical battery, a battery factory generally adopts a method of inserting a core rod into a central hole. The core bone is inserted into the central hole, so that the space of the pole group extruded inwards due to expansion is reduced, the deformation of the pole group is reduced, the occurrence of side reactions such as lithium precipitation, gas generation and fragment in the battery is reduced, and the service life of the battery is prolonged.

The prior art has the following defects: because the electrode group needs to be pre-rolled for several circles of diaphragms in the winding process and then is respectively inserted into the positive and negative electrode plates, the winding needle is pulled out after the electrode group is wound, and the diaphragm contracts inwards after the central hole loses the support of the winding needle, so that the central hole becomes small. Although the hole ironing process (ironing and shaping the diaphragm with the central hole by using the through holes with temperature) is added, the diaphragm is very thin and made of PP or PE, and slight rebound is generated. If the core rod with the same diameter as the winding needle is used, the core rod is difficult to insert into the central hole of the pole group, and the diaphragm is very thin and easy to contort, so that the pole group is scrapped, and therefore a battery factory generally inserts the core rod with the diameter smaller than the winding needle by 0.5-1 mm into the central hole.

This results in the pole group having a space for internal expansion even if the core is inserted, and the core cannot fully function to support the pole group. With the increase of the cycle times, the pole piece is extruded inwards to generate deformation, and side reactions such as lithium precipitation, gas generation and the like are generated. With the aggravation of chain reaction, the phenomenon of battery cycle water-jumping still exists.

Disclosure of Invention

The invention provides a method for using an expandable core bar to solve the technical problems in the prior art, wherein the expandable core bar is used, so that the inward expansion space of a pole group is reduced to play a better supporting role, the pole piece wrinkles caused by pole piece deformation in the battery circulation process are reduced, and a series of chain reactions of lithium precipitation, gas generation, pole piece pulverization, material dropping, fracture and the like of the battery are further reduced.

The invention aims to provide a using method of an expansion core rod, wherein the expansion core rod comprises the following components:

an outer sleeve made of an elastic material; the outer wall of the outer sleeve is provided with a fracture seam from one end to the other end;

an inner sleeve made of a rigid material; wherein:

the inner diameter of the outer sleeve is smaller than the outer diameter of the inner sleeve;

the using method comprises the following steps:

s1, inserting the outer sleeve into the central hole of the pole group;

and S2, inserting the inner sleeve into the outer sleeve.

Preferably, the fracture seam is a straight seam parallel to the central axis of the outer sleeve.

Preferably, the outer sleeve is a plastic sleeve.

Preferably, the inner casing is a stainless steel tube.

Preferably, one end of the outer sleeve is a conical head, and the other end of the outer sleeve is a flat head.

Preferably, at least one end of the inner sleeve is a conical head.

The invention has the advantages and positive effects that:

the invention uses the expandable core, reduces the inward expansion space of the pole group to play a better supporting role, reduces the pole piece wrinkles caused by the pole piece deformation in the battery circulation process, and further reduces a series of chain reactions of battery lithium precipitation, gas generation, pole piece pulverization, material dropping, fracture and the like. The expansion core rod not only plays a better supporting role, but also is simple to operate in the insertion process without damaging the diaphragm, and the diameter of the core rod can be adjusted according to the requirement;

according to the invention, by embedding the plastic sleeve in advance and then inserting the core bone, the outer diameter of the core bone can be expanded to any size which is required by people, and the insertion process is simple, so that the risks of insertion injury, contusion and the like on the pole group can be avoided. And the expansion core can play a full supporting effect on the inside of the pole group after being inserted, so that the problem of pole piece deformation and damage caused by inconsistent stress inside the pole group due to nonuniform expansion is avoided. The expansion core has the advantages that the expansion space of the pole group is reduced to the maximum extent, the risk of pole piece fold powder falling and breaking caused by the expansion of the pole group is reduced, the cycle life of the cylindrical lithium ion battery is prolonged, the pole group at the last stage of the cycle can be supported, and the cycle life of the cylindrical lithium ion battery is prolonged greatly.

Drawings

FIG. 1 is a front view of an expanded mandrel in accordance with a preferred embodiment of the present invention;

FIG. 2 is an axial sectional view of an expanded mandrel in accordance with a preferred embodiment of the present invention;

FIG. 3 is a front view of the inner sleeve in the preferred embodiment of the present invention;

FIG. 4 is a front view of the outer sleeve in the preferred embodiment of the present invention;

FIG. 5 is a block diagram of the inner cannula in the preferred embodiment of the invention;

Detailed Description

In order to further understand the contents, features and effects of the present invention, the following embodiments are illustrated and described in detail with reference to the accompanying drawings:

the noun explains: the core rod and the lithium ion battery pole group are wound by using the winding needle in the winding process, the winding needle is drawn out after winding, and a central hole with the thickness of the winding needle is formed in the middle of the pole group. During the production process, a bar (generally a steel pipe or an aluminum pipe) is inserted into the central hole to play a role of supporting the pole group, and the inserted bar is the core rod.

The technical scheme of the invention is as follows:

a method of using an expanded core, as shown in fig. 1 to 4, the expanded core comprising:

an outer sleeve made of an elastic material; the outer wall of the outer sleeve is provided with a fracture seam from one end to the other end;

an inner sleeve made of a rigid material; wherein:

the inner diameter of the outer sleeve is smaller than the outer diameter of the inner sleeve;

the using method comprises the following steps:

s1, inserting the outer sleeve into the central hole of the pole group;

and S2, inserting the inner sleeve into the outer sleeve.

In the preferred embodiment described above, the fracture seam is a straight seam parallel to the central axis of the outer sleeve.

The expandable mandrel of the preferred embodiment is comprised of two main parts, an outer casing (e.g., a plastic casing) made of an elastomeric material and an inner casing (e.g., a stainless steel tube) made of a rigid material. The plastic sleeve is provided with a fracture seam (also known as a slit) which is communicated up and down, one end of the plastic sleeve is a conical head, the other end of the plastic sleeve is a flat head, and one end of the stainless steel pipe is a conical head or both ends of the stainless steel pipe are conical heads. The plastic casing pipe and the stainless steel pipe are smooth in surface, free of burrs, corrosion, scratches, bumps and other adverse problems.

The use principle is as follows: firstly, the conical head side of the plastic sleeve is inserted into the central hole of the pole group, the outer diameter of the plastic sleeve is smaller than the diameter of the central hole, and the plastic sleeve can be easily inserted without damaging the pole group. And lightly inserting the stainless steel pipe into the plastic sleeve, wherein the outer diameter of the stainless steel pipe is slightly larger than the inner diameter of the plastic sleeve, and after the stainless steel pipe is inserted into the plastic sleeve, the outer diameter of the plastic sleeve is increased to be the sum of the outer diameter of the stainless steel pipe and the wall thickness of the plastic sleeve. The outer diameter of the expanded plastic sleeve is not larger than or slightly exceeds the inner diameter of the central hole of the pole group, so that the pole group is prevented from being damaged after the core bone is expanded. The expanded plastic sleeve pipe should expand uniformly to ensure that the joint surface of the plastic sleeve pipe and the pole group is uniformly contacted with the joint of the expansion-removing slit to play a role in supporting the pole group comprehensively. The plastic sleeve is made of PP materials or other materials which do not participate in the internal reaction of the battery and has certain elastic toughness. The inserted bar can be a pipe bar which does not participate in the internal reaction of the battery and has certain strength, such as a stainless steel pipe, an aluminum pipe, a plastic pipe and the like.

Referring to fig. 5, a cylindrical battery includes an expansion core 6 in the above preferred embodiment, a battery pole group is provided with a central hole 5, the battery pole group with an insulation diaphragm 7 is sleeved outside the expansion core, the battery pole group includes a positive pole group 9 and a negative pole group 11, a negative pole tab 10 is installed on the negative pole group 11, insulation sheets (an upper insulation sheet 4 and a lower insulation sheet 8) are provided at two ends of the battery pole group, and a cap 3 is installed on the upper insulation sheet 4.

This application can insert the bigger core bone of diameter in the utmost point group centre bore and can not harm the diaphragm utmost point group, can be better play the supporting role to utmost point group, reduced battery later stage circulation because of the utmost point circulation that the group collapses circulation diving scheduling problem that leads to.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications, equivalent changes and modifications made to the above embodiment according to the technical spirit of the present invention are within the scope of the technical solution of the present invention.