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CN-122025838-A - Helium filling device and helium filling method for lithium battery

CN122025838ACN 122025838 ACN122025838 ACN 122025838ACN-122025838-A

Abstract

The invention relates to the technical field of lithium battery manufacturing, and discloses a helium injection device and a helium injection method thereof for a lithium battery, wherein the helium injection device comprises a bottom cover; the top cover is arranged at the output end of the first telescopic piece, the top cover is sleeved in the bottom cover, the top cover is provided with a first air suction hole and a first air injection hole, the top cover is also in threaded connection with a hollow pipe, one end of the hollow pipe outside the top cover is respectively provided with a second air suction hole and a second air injection hole, and the sealing component is arranged at one end of the hollow pipe, which is positioned in the top cover, and controls the switch of the end of the hollow pipe. By arranging the sealing cavity matched with the inner cavity volume of the battery shell and synchronously vacuumizing and injecting air, the internal pressure and the external pressure of the battery shell are kept in dynamic balance all the time in the vacuumizing and helium injecting process, the pressure difference which leads to the sinking or expansion of the battery shell is fundamentally eliminated, the deformation of the battery shell is effectively prevented, and the integrity and the reliability of the battery structure are ensured.

Inventors

  • WEN ZHIQIANG

Assignees

  • 国科能源(滁州)有限公司

Dates

Publication Date
20260512
Application Date
20260225

Claims (8)

  1. 1. A helium filling device for a lithium battery, comprising a bracket (1) and a first telescopic member (2), characterized in that the device further comprises: a bottom cover (3), wherein the bottom cover (3) is arranged on the bracket (1); The top cover (4), the top cover (4) is installed at the output end of the first telescopic part (2), the top cover (4) is sleeved in the bottom cover (3), the top cover (4) is provided with a first air pumping hole (41) and a first air injecting hole (42), the top cover (4) is further connected with a hollow pipe (43) in a threaded mode, one end of the hollow pipe (43) extends into the top cover (4), the end of the hollow pipe (43) is communicated with the liquid injecting hole in the lithium battery cover plate, and one end of the hollow pipe (43) outside the top cover (4) is provided with a second air pumping hole (431) and a second air injecting hole (432) respectively; and the sealing component (6) is arranged at one end of the hollow tube (43) in the top cover (4), and the sealing component (6) controls the switch at the end of the hollow tube (43).
  2. 2. The helium filling device for the lithium battery according to claim 1, wherein a sealing plate (5) is movably installed in the top cover (4), a supporting rod (51) is arranged on one surface of the sealing plate (5), the supporting rod (51) penetrates through and stretches out of the top cover (4), a plug pin (52) is movably arranged outside the top cover (4), a plurality of plug holes are formed in the supporting rod (51), and the plug pin (52) is sleeved in the plug holes.
  3. 3. The helium filling device of a lithium battery according to claim 1, wherein the sealing component (6) comprises a first sliding plate (61) and a second sliding plate (62), two sides of the first sliding plate (61) are respectively provided with an upper blocking plate (611), two sides of the second sliding plate (62) are respectively provided with a lower blocking plate (621), the upper blocking plates (611) are flush with the top of the first sliding plate (61), the lower blocking plates (621) are flush with the bottom of the second sliding plate (62), the upper blocking plates (611) and the lower blocking plates (621) are stacked together, gaps (63) are formed between the first sliding plate (61) and the second sliding plate (62) after staggering, sliding grooves (64) are respectively formed in the outer sides of the upper blocking plates (611) and the lower blocking plates (621), two groups of clamping blocks (69) are arranged in the outer sides of the hollow tube (43), and the clamping blocks (69) are sleeved in the sliding grooves (64).
  4. 4. The helium filling device for the lithium battery according to claim 3, wherein wedge-shaped grooves (65) are formed in the first sliding plate (61) and the second sliding plate (62), the two groups of wedge-shaped grooves (65) are symmetrical, two groups of sleeves (67) are symmetrically arranged on the outer side of the hollow tube (43), a push plate (66) is movably installed in the sleeve (67), an elastic piece I (671) is connected between the push plate (66) and the sleeve (67), the push plate (66) penetrates through the wedge-shaped grooves (65), a wedge-shaped part (661) is arranged on the push plate (66), the wedge-shaped part (661) is matched with the wedge-shaped grooves (65), side plates (68) are arranged on the first sliding plate (61) and the second sliding plate (62), and an elastic piece II (681) is connected between the side plates (68) and the hollow tube (43).
  5. 5. The helium filling device for a lithium battery according to claim 4, wherein a plugging component (7) is installed in the hollow tube (43), the plugging component (7) comprises a fixed cylinder (71), the fixed cylinder (71) is fixed in the hollow tube (43), the bottom end of the fixed cylinder (71) is in an opening state, a sealing nail (74) is placed at the bottom end of the fixed cylinder (71), the sealing nail (74) plugs the bottom end of the fixed cylinder (71), a second telescopic part (72) is installed in the fixed cylinder (71), the output end of the second telescopic part (72) faces the sealing nail (74), a storage barrel (73) is arranged on the side face of the fixed cylinder (71), and a plurality of sealing nails (74) are stored in the storage barrel (73).
  6. 6. The helium filling device for the lithium battery according to claim 1, wherein four groups of guide rails (31) are arranged on the bottom cover (3), clamping plates (8) are movably arranged on the guide rails (31), studs for fixing the clamping plates (8) are arranged on the clamping plates (8), a plurality of clamping pieces (9) are arranged on the clamping plates (8), and the clamping pieces (9) on the four groups of clamping plates (8) clamp four surfaces on the periphery of the lithium battery shell.
  7. 7. The helium filling device for a lithium battery according to claim 6, wherein the clamping piece (9) comprises a sealing cylinder (91), a piston rod (92), a sliding rod (95) and a sucker (96), the sealing cylinder (91) is fixed on the clamping plate (8), the piston rod (92) is movably mounted in the sealing cylinder (91), gas is stored between the piston rod (92) and the sealing cylinder (91), the sliding rod (95) is movably mounted on the sealing cylinder (91), the sucker (96) is arranged at one end of the sliding rod (95), the sucker (96) faces the lithium battery shell, a toothed plate I (93) is arranged on the piston rod (92), a gear (94) is rotatably mounted on the sealing cylinder (91), a toothed plate II (97) is arranged on the sliding rod (95), and the toothed plate I (93) and the toothed plate II (97) are meshed with the gear (94).
  8. 8. A helium filling method for a helium filling device for a lithium battery, which is applied to the helium filling device for a lithium battery according to any one of the claims 1 to 7, and comprises the following steps: step S1, placing a battery in a cavity formed by a top cover (4) and a bottom cover (3), and communicating a hollow tube (43) with a battery liquid injection hole; Step S2, synchronously vacuumizing the cavity and the battery to dynamically balance the pressure of the cavity and the battery; Step S3, helium is synchronously filled into the cavity and the battery to synchronously raise the pressure of the cavity and the battery to a target value; And S4, sealing the battery liquid injection hole to finish helium injection.

Description

Helium filling device and helium filling method for lithium battery Technical Field The invention relates to the technical field of lithium battery manufacturing, in particular to a helium injection device and a helium injection method for a lithium battery. Background In the manufacturing process of square lithium ion batteries, two helium injection operations are generally required to ensure the long-term sealing reliability and the internal environmental stability of the batteries. The first helium injection occurs before the welding of the battery case cover plate, and the main purpose of the first helium injection is to detect the air tightness of the empty battery case. By filling helium into the shell and detecting leakage conditions, the problem of weld defects or incomplete structure of the shell can be found in advance, so that potential safety hazards and performance loss caused by leakage after electrolyte is subsequently injected are avoided. The second helium injection is performed after the welding of the battery cover plate is completed. The process aims at replacing the internal atmosphere of the battery, and establishes a stable and dry inert gas environment so as to reduce the adverse effects of residual moisture and oxygen in the battery on electrode materials and electrolyte, thereby improving the electrochemical performance, the cycle life and the storage stability of the battery. The traditional secondary helium injection process generally adopts a mode of pumping negative pressure and then backfilling helium, namely, firstly vacuumizing the sealed battery to form a negative pressure state, and then backfilling helium into the battery to restore the internal pressure of the battery to a micro negative pressure or micro positive pressure state. However, the conventional method has the obvious defect in practical application that since the square battery case is generally made of a metal sheet, the external atmospheric pressure can generate a large squeezing action on the side surface of the battery in the process of vacuumizing to form negative pressure, and the inward concave plastic deformation of the battery side plate is easily caused. Such deformation not only affects the appearance of the battery, but also reduces the mechanical strength and overall reliability of the battery case. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a helium injection device and a helium injection method for a lithium battery, so as to achieve the aim of effectively preventing the deformation of a battery shell under the premise of not influencing the helium injection process effect. The aim of the invention can be achieved by the following technical scheme: a lithium battery helium filling device, comprising a support and a first telescopic member, the device further comprising: the bottom cover is arranged on the bracket; The top cover is arranged at the output end of the first telescopic piece, the top cover is sleeved in the bottom cover, the top cover is provided with a first air suction hole and a first air injection hole, the top cover is also in threaded connection with a hollow pipe, one end of the hollow pipe extends into the top cover, the end of the hollow pipe is communicated with the liquid injection hole on the lithium battery cover plate, and one end of the hollow pipe outside the top cover is provided with a second air suction hole and a second air injection hole respectively; and the sealing component is arranged at one end of the hollow pipe positioned in the top cover, and controls the switch at the end of the hollow pipe. As a further scheme of the invention, a sealing plate is movably arranged in the top cover, one surface of the sealing plate is provided with a supporting rod, the supporting rod penetrates through and extends out of the top cover, a bolt is movably arranged outside the top cover, a plurality of jacks are formed in the supporting rod, and the bolt is sleeved in the jacks. As a further scheme of the invention, the sealing assembly comprises a first sliding plate and a second sliding plate, wherein the two sides of the first sliding plate are respectively provided with an upper blocking plate, the two sides of the second sliding plate are respectively provided with a lower blocking plate, the upper blocking plates are flush with the top of the first sliding plate, the lower blocking plates are flush with the bottom of the second sliding plate, the upper blocking plates and the lower blocking plates are stacked together, gaps are formed between the first sliding plate and the second sliding plate after the first sliding plate and the second sliding plate are staggered, sliding grooves are respectively formed in the outer sides of the upper blocking plates and the lower blocking plates, two groups of clamping blocks are arranged in the outer sides of the hollow pipes, and the clamping blocks are sleeved in the sliding