US-20260124633-A1 - THICK ELECTRODE COATING APPARATUS FOR SECONDARY BATTERIES

US20260124633A1US 20260124633 A1US20260124633 A1US 20260124633A1US-20260124633-A1

Abstract

Present invention discloses a thick electrode coating apparatus for secondary batteries, specifically relating to lithium battery electrode processing technology. The apparatus comprises a mounting frame, wherein the filtration device and the feed conveying device are fixedly mounted on the mounting frame. A storage device is provided at the rear portion of the mounting frame, and a coating device is slidably mounted on the upper portion of the mounting frame. The thick electrode coating apparatus for secondary batteries of the present invention enables one-time coating of thick electrodes using high-viscosity slurry. Meanwhile, the apparatus can solve a series of problems occurring during high-viscosity slurry coating, such as foil leakage, uneven thickness, and low production efficiency, thereby effectively improving coating capability and quality.

Inventors

Junyong Wang

Assignees

BoRuoNieLi (Beijing) Equipment Technology Co., Ltd

Dates

Publication Date: 20260507
Application Date: 20241211
Priority Date: 20241107

Claims (10)

1 . A thick electrode coating apparatus for secondary batteries, comprising a mounting frame ( 1 ), a circulation delivery pump ( 3 ), a feed delivery pump ( 4 ), a filtration device ( 5 ), a feed conveying device ( 6 ), a feed pipeline I ( 7 ), and a circulation pipeline I ( 8 ), characterized in that: the circulation delivery pump ( 3 ) and the feed delivery pump ( 4 ) are fixedly installed on the upper rear portion of the mounting frame ( 1 ), the filtration device ( 5 ) and the feed conveying device ( 6 ) are fixedly mounted on the upper middle portion of the mounting frame ( 1 ), the filtration device ( 5 ) is positioned between the circulation delivery pump ( 3 ) and the feed conveying device ( 6 ), the circulation delivery pump ( 3 ), filtration device ( 5 ), and feed conveying device ( 6 ) are connected in series by the feed pipeline I ( 7 ); The storage device ( 2 ) is provided at the rear portion of the mounting frame ( 1 ), the output end of the storage device ( 2 ) is connected in series with the feed delivery pump ( 4 ) through the circulation pipeline I ( 8 ), the output end of the circulation delivery pump ( 3 ) is connected to the input end of the storage device ( 2 ), and a coating device ( 9 ) is mounted to slide on the upper left portion of the mounting frame ( 1 ).
2 . The thick electrode coating apparatus for secondary batteries according to claim 1 , characterized in that: the storage device ( 2 ) comprises a storage tank ( 21 ), the top of the storage tank ( 21 ) is symmetrically installed with a return pipe and a feed pipe at front and rear positions respectively, the bottom of the storage tank ( 21 ) is installed with a discharge pipe, a motor ( 24 ) is installed at the central position of the top wall of the storage tank ( 21 ), a connecting rod is installed at the output end of the motor ( 24 ) through a coupling, a stirring paddle ( 22 ) is installed at the lower end of the connecting rod, the input end of the feed delivery pump ( 4 ) is connected to the discharge pipe through the circulation pipeline I ( 8 ), and the output end of the circulation delivery pump ( 3 ) is connected to the return pipe through the feed pipeline I ( 7 ).
3 . The thick electrode coating apparatus for secondary batteries according to claim 1 , characterized in that: the coating device ( 9 ) comprises multiple guide rails ( 92 ) installed on the upper front portion of the mounting frame ( 1 ), buckles ( 91 ) are mounted to slide on the outer surface of each guide rail ( 92 ), the base II ( 93 ) is jointly fixed on the upper end of multiple buckles ( 91 ), the base I ( 94 ) is provided on the upper end of the base II ( 93 ), multiple support bracket I ( 95 ) are fixed at the rear portion of the base I ( 94 ), a connecting plate is jointly fixed at the front end of multiple support bracket I ( 95 ), a coating structure ( 96 ) is fixed on the upper end of the base I
( 94 ) and multiple coating head pressure roller drives ( 97 ) are provided at the rear end of the base II ( 93 ) and mounted on the upper end of the mounting frame ( 1 ).
4 . The thick electrode coating apparatus for secondary batteries according to claim 3 , characterized in that: the coating structure ( 96 ) comprises a coating valve seat I ( 962 ) fixed on the upper end of the horizontal portion of the base I ( 94 ) and multiple coating valve I drive ( 961 ) installed at the front portion of the base I ( 94 ), a sliding slot I ( 963 ) is formed at the front portion of the upper end of the coating valve seat I ( 962 ), an arc-shaped groove ( 965 ) is formed at the rear portion of the upper end of the coating valve seat I ( 962 ), multiple coating valve I ( 964 ) are mounted to slide within the sliding slot I ( 963 ), a coating valve seat II ( 966 ) is fixed at the middle front end of the vertical portion of the base I ( 94 ), a baffle plate ( 976 ) is mounted to slide at the middle upper end of the coating valve seat II ( 966 ), multiple coating valve II ( 968 ) are provided at the front end of the coating valve IV ( 967 ), a coating valve III ( 969 ) is mounted to slide on the upper end of the coating valve IV ( 967 ) and multiple coating valve II ( 968 ), baffle plates ( 976 ) are installed at both the left and right portions of the front end of the coating valve IV ( 967 ), and the two baffle plates ( 976 ) are positioned at the left side of the leftmost coating valve II ( 968 ) and the right side of the rightmost coating valve II ( 968 ) respectively; multiple circulation pipeline III ( 972 ) are fixed on the upper end of each coating valve II ( 968 ); multiple chutes ( 971 ) corresponding to the circulation pipeline III ( 972 ) on the same side are formed on the upper end of the coating valve III ( 969 ), and multiple circulation pipeline III ( 972 ) are positioned within multiple chutes ( 971 ) respectively; the coating valve II ( 968 ) and the coating valve III ( 969 ) are arranged in multiple sets along the substrate movement direction; the input ends of the circulation pipeline I ( 8 ) are installed at the middle left end and middle right end of the base I ( 94 ) and both communicate with the interior of the arc-shaped groove ( 965 ).
5 . The thick electrode coating apparatus for secondary batteries according to claim 4 , characterized in that: multiple coating valve III drive ( 973 ), multiple coating valve IV drive ( 974 ), and multiple coating valve II drive ( 975 ) are installed at the front end of the connecting plate, the output piston rods of multiple coating valve IV drive ( 974 ) penetrate through the vertical portion of the base I ( 94 ) and are connected to the rear end of the coating valve IV ( 967 ) respectively, the output piston rods of multiple coating valve II drive ( 975 ) penetrate through the vertical portion of the base I ( 94 ) and are connected to the coating valve II ( 968 ) on the same side respectively, multiple coating valve IV drive ( 974 ) are evenly distributed on both left and right sides of multiple coating valve II drive ( 975 ), and the output piston rods of multiple coating valve III drive ( 973 ) penetrate through the vertical portion of the base I ( 94 ) and are jointly connected to the rear end of the coating valve III ( 969 ).
6 . The thick electrode coating apparatus for secondary batteries according to claim 5 , characterized in that: the lower portion of the outer surface of multiple coating valve II ( 968 ) facing the backing roller ( 10 ) is formed in an arc shape, an arc groove ( 9683 ) is formed on the upper portion of the outer surface of the coating valve II ( 968 ) facing the backing roller ( 10 ), a pressure sensor II ( 9682 ) is installed at the middle portion of the inner surface of the arc groove ( 9683 ), and a reflow hole ( 9681 ) communicating with the interior of the circulation pipeline III ( 972 ) on the same side is formed at the front portion of the inner surface of the arc groove ( 9683 ).
7 . The thick electrode coating apparatus for secondary batteries according to claim 4 , characterized in that: the lower front end of the coating valve seat II ( 966 ) is processed with rounded corners and installed with a pressure sensor I ( 9661 ).
8 . The thick electrode coating apparatus for secondary batteries according to claim 4 , characterized in that: the lower front end of the coating valve III ( 969 ) is structured in an arc shape, flat shape, irregular shape, or adjustable configuration.
9 . The thick electrode coating apparatus for secondary batteries according to claim 3 , characterized in that: a coating head transverse movement drive device is installed between the base II ( 93 ) and the base I ( 94 ).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The application claims priority to Chinese patent application No. 2024115872482, filed on Nov. 7, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The invention relates to the field of lithium battery electrode processing technology, particularly to a thick electrode coating apparatus for secondary batteries. BACKGROUND In the manufacturing process of secondary batteries, the primary purpose of the front-end process is to produce battery electrodes (taking lithium batteries as an example, the same applies below), mainly including mixing, coating, and rolling processes. The coating process involves applying battery slurry (hereinafter referred to as slurry) onto the surface of the battery current collector (hereinafter referred to as substrate), which forms electrodes after drying. As is well known, current lithium batteries face challenges of low energy density and high cost, thus improving energy density and reducing cost are objectives pursued by all battery manufacturers. For substrates of the same thickness, applying thicker slurry coatings to achieve higher surface density effectively reduces the proportion of auxiliary materials such as substrates and separators in batteries, thereby significantly improving battery energy density and reducing battery cost. Therefore, producing thick electrodes or high surface density electrodes is a direction all battery manufacturers are striving toward. The challenge in coating thick electrodes lies in ensuring coating thickness uniformity. Conventional squeeze coating heads or transfer coating heads in the market are adapted to slurry with relatively low viscosity, with production line coating viscosity windows approximately 1500-12000 CP. When coating thick electrodes with low-viscosity slurry, due to good slurry fluidity, thick wet films are affected by pressure balance during internal transportation within the coating head, gravity effects after coating, and uniformity of hot air during baking, making it difficult to maintain a fixed shape on the substrate surface, resulting in poor thickness uniformity that fails to meet usage requirements. Using double-layer coating heads can solve the pressure balance issue during internal transportation, enabling the coating of thicker wet film electrodes, but cannot resolve thickness uniformity issues caused by external forces such as gravity and air uniformity acting on highly fluid slurry. Additionally, the interface resistance between the two wet film layers coated by double-layer coating heads is high, resulting in poor electrode performance. Therefore, an effective method for one-time thick electrode coating is to increase slurry viscosity. However, after increasing slurry viscosity, the slurry's fluidity decreases, lacks leveling properties, and its rheological characteristics become more pronounced, making it impossible for current market transfer coating heads and conventional squeeze coating heads to coat high-viscosity slurry. In conclusion, coating high surface density thick electrodes and coating high-viscosity slurry have become challenging research topics in the new energy industry. SUMMARY The main objective of this invention is to provide a thick electrode coating apparatus for secondary batteries that effectively resolves the problems mentioned in the background technology. To achieve this objective, the technical solution adopted by this invention is as follows: A thick electrode coating apparatus for secondary batteries comprises a mounting frame, circulation delivery pump, feed delivery pump, filtration device, feed conveying device, feed pipeline I, and circulation pipeline I. The circulation delivery pump and feed delivery pump are fixed on the upper rear portion of the mounting frame. The filtration device and feed conveying device are fixedly mounted on the upper middle portion of the mounting frame. The filtration device is positioned between the circulation delivery pump and feed conveying device, with these components connected in series by the feed pipeline I. A storage device is provided at the rear portion of the mounting frame. The output end of the storage device is connected in series with the feed delivery pump through the circulation pipeline I. The output end of the circulation delivery pump is connected to the input end of the storage device, and a coating device is mounted to slide on the upper left portion of the mounting frame. Preferably, the storage device includes a storage tank with symmetrically installed return and feed pipes at the front and rear of its top. A discharge pipe is installed at the bottom of the storage tank. A motor is installed at the central position of the tank's top wall, with a connecting rod installed through a coupling at the motor's output end. A stirring paddle is installed at the lower end of the connecting rod. The input end of the feed delivery pump connects to the discharg