Lithium Battery Cell

Mixing Systems For Electrode Production

Mixing process is to make slurry by active material, conductive material, binder and solvent, and ensure uniform distribution by accurately inputting through metering, mixing and steaming by powder supply device.

The mixing process usually consists of the following process:

Supplying powder (active material, etc) to mixer

Pre-dispersion of binder or conductive material before main mixing for mixing efficiency

Main mixing of active material, conductive material, binder, etc.

Storing the produced slurry and transferring it to the next process, the coating process

POWDER TRANSFER SYSTEMS for Electrode production

PTS (Powder Transfer System) is to transfer powder quantitively and smoothly by using air or vacuum.

PD Mixer

PD mixer has twist blades to generate big power for kneading and stirring, and have despair for high speed dispersion at the same time.

Because of efficient mixing and high volume, PD mixer is the most common mixer used in manufacturing secondary battery slurry equipment

Mixing Systems For Electrode Production

Coating Process

Coating process is a key process in battery manufacturing, and is a facility for coating and drying cathode slurry and anode slurry on metal foils such as aluminum and copper.

In many cases, slot dies are used as the coating method, but we can propose continuous coating, intermittent coating, double-sided simultaneous coating, etc. according to the customer’s electrode manufacturing process.

Coater Standard Specification

Winding Type: Auto Turret

Coating Width: Max. 1400mm (Anode), Nor. 680mm

Machine Speed: 80m/min

Coating Speed: Nor. 70m/min (18mg/cm2)

Coating Type: Slot Die

Coating Mode: Stripe & Intermittent

Coating Thickness: Nor. 200µm (One side)

Foil Feeding Type: Roll Support

Drying Zone: 1F/L 5m x 12 zones = 60m / 2F/L 5m x 12 zones = 60m

Heating source: 1. Electric heater 2. Steam 3. Hot oil

Option: Loading Density Measuring, Ceramic Coating

Delivery: 12 months (FOB)

*This specification is a standard specification, and we can make proposals according to the customer’s electrode manufacturing process.y

Coating Process line

Roll Pressing                                                                                                                                                                                                                                                  This equipment unwinds a thin film of aluminum foil, copper foil, etc. coated with an active material, continuously compresses it with a press roll, and winds it up. It is used to increase the filling factor of the active material applied to the thin film.

Single Calendar (Auto Turret)

Pressing Unit

Roll Press Standard Specification

Calendar Thickness Quality : ± <2um

Winding Type: Auto Turret

Calendaring Width: Nor. 680mm, Max. 1400mm (Anode)

Machine Speed: Max. 110m/min

Calendaring Speed: Max.100m/min, Nor. 80m/min

Calendaring Gap Control: 1. Screw Servo, 2. Hydraulic Servo

Calendaring Main Roll: Hot oil heat source

Calendaring Pressure: Max. 6Ton/cm, Nor. 4Ton/cm

Option:

1. Auto Thickness Gauge (Auto Feed Back System)

2. Force Elongation

3. IHU

*This specification is a standard specification, and we can make proposals according to the customer’s electrode manufacturing process.

Roll Pressing

Slitting

Charge and discharge equipment is one of the most important processes in lithium-ion battery manufacturing to determine the quality of lithium-ion batteries by repeatedly charging and discharging them at a specified current, voltage, and temperature. Charge and discharge testing is one of the most important processes in lithium-ion battery manufacturing. High-precision charge/discharge inspection, excellent safety, and energy saving are required at the same time. We manufacture advanced charge/discharge testing equipment based on our unique electrical control technology, and have sold many of these products to users in Japan and overseas. In addition to our existing power supply line up, we develop power supplies to meet required specifications, and can handle everything from testing equipment to mass production machines.

Slitter

The slitter for LIB unwinds a roll of metal foil or an electrode plate, continuously cuts (slits) it to an arbitrary width, and rewinds it into a roll. We can also propose waste material collection equipment after slitting.

Slitter Standard Specification

Slitting Knife: Gang + Shear

Slitting Width: Max. 1400mm

Slitting Lane: Max. 2 ~ 11 lanes

Slitting Speed: Max. 100m/min, Nor. 70m.min

Option: Visual Inspection System

Cylindrical Type (Auto Turret)

Integration: Calendar + SlittingC

Slitting

Winding Machines for Cylindrical Batteries

This machine is for the cylindrical battery manufacturing equipment. After the equipment is used for positive and negative film unwinding and rectification, the positive/negative tab is ultrasonically welded and glued. After the electrode is inserted into the film, it is wound into a cylindrical battery cell together with the separator. After cutting/ attaching protective tape/ hot hole and measuring/ the short circuit checked, it is finally sent out by the conveyor belt.

Main Parameters and Functions

Electrode automatic roll change

Separator automatic roll change

Segmented tension automatic Control

Ultrasonic welding system

Dust removal system

Hi-pot testing function

Three-axis automatic winding

Positive and negative electrode tape device

Double station cutting, high speed stability

Edge positioning correction control

Cell hot hole

Winding Machines for Prismatic Batteries

The equipment is mainly used for the winding of the prismatic battery cell, the coil material is supplied to the electrode and the separator, and the positive and negative electrode sheets and the diaphragm are wound to complete the cell bare core. Three-station operation: one station into the film winding, two stations for finishing glue, three stations for unloading. Automatic test for short circuit, weighing, and defective product rejection.

Main Functions

Dust removal system

Segmented tension

Automatic control

PC control

Positive electrode cutting and taping device

CCD overhang detection

Battery shape detection

Hi-pot test function

Electrode automatic roll change

Separator automatic roll change

3 axles automatic roll change.

Winding Machines

Stacking Machine

The equipment is used for Z-shaped lamination of positive and negative electrode sheets of lithium ion battery cells, U-shaped glue sticking on cells, short-circuit testing, cell blanking and other functions.

Flow of Electrode Stacking

Electrode Preparation:

Before stacking, individual electrode layers are prepared. This involves coating or depositing active materials onto current collectors, which could be conductive substrates like metal foils. These active materials are chosen based on the type of electrochemical device and the desired electrochemical reactions.

Separator Integration:

Separators, which are typically ion-conductive membranes or materials, are often placed between adjacent electrode layers. Separators prevent electrical short circuits between electrodes while allowing ions to pass through. In solid-state devices like solid oxide fuel cells (SOFCs), separators could be solid electrolytes.

Electrode Stacking:

Once the electrodes and separators are prepared, they are stacked in a specific order to form a layered structure. The order of stacking depends on the type of device and the intended electrochemical reactions. For example, in a lithium-ion battery, the typical order could be: cathode – separator – anode.

Electrode Alignment:

Proper alignment of electrodes and separators is crucial to ensure optimal electrochemical performance. Misalignment could lead to uneven distribution of reactants, reduced efficiency, or even short circuits.

Sealing:

In devices that require containment of reactants and products, the stacked layers are often sealed around the edges to prevent leakage. This sealing process ensures that the electrochemical reactions occur within the designated areas

Stacking Machine

Vacuum Roll to Roll Drying System

Suitable for drying cathode/anode electrodes

Features for Vacuum Roll to Roll (R to R) drying system

Energy Saving

By adopting a continuous process, our product eliminates the need for cooling down at each stage of a batch process. This significantly minimizes energy loss, leading to considerable energy savings and the development of more environmentally friendly processes.

Uniform Heating

R to R drying is a continuous process where the electrode material is coated onto a flexible substrate in a continuous web format. Compared to conventional roll drying, R to R processing provides uniform product quality.

Reduced Drying Time

R to R drying is designed for high-throughput production, making it suitable for large-scale manufacturing. It allows for the efficient processing of electrode materials in large volumes. Compared to conventional roll drying, R to R processing significantly reduces processing time. (12hr→0.6hr).

Cost Efficiency

R to R processes are cost-efficient for large-scale production due to minimal downtime and reduced manual intervention. They are highly automated, streamlining production.

Space Saving

The vertical arrangement of the heaters reduce the installation space to 1/10 compared to the horizontal arrangement.

Lead time reduction

By adopting a gate valve mechanism, the lead time for product replacement is greatly reduced.

Conventional roll drying in batch process compared with Vacuum Roll to Roll drying system

Batch vacuum drying system requires a lot of factory space compared with R to R system.

Differences between batch vacuum heating systems

Heat treatment

The biggest difference between the batch type roll drying process and our R to R drying system is how we can treat uniform heating to the electrodes. Companies that manufacture electrodes where they have drying process in the production line, they usually face a problem called “Spring back Effect”. This is caused when there are temperature differences between the inner part and the outer part of the electrode roll, which then causes the cathode/anode materials to “Spring back” even though they are pressed in the previous processes.

Energy Saving

Since the conventional vacuum heating systems uses nitrogen (N2) to make a “vacuum” atmosphere, the operational cost is significantly high. Also, the structure of the R to R drying system has a significantly smaller chamber than the conventional systems, power consumption is also dramatically lower. It is estimated have approx. 50% lower power consumption and 100% less nitrogen (not necessary) compared to conventional systems which also has a large impact to CO2 emission!

Vacuum Roll to Roll Drying System

Assembly Process For Cylindrical, Square And Prismatic Batteries

General processes for every type of batteries

Electrolyte Filling (Liquid Electrolyte)

In traditional lithium-ion batteries using liquid electrolytes, the electrolyte injection process is a critical step. An opening or port is created in the battery casing to facilitate this. The liquid electrolyte, a lithium salt dissolved in a solvent, is injected into the cell through this opening. The specific electrolyte composition can vary depending on the battery design and intended application.

Venting and Degasification

After electrolyte injection in both liquid and solid-state batteries, a degasification process is often conducted to remove any remaining gas or air from the cell. This ensures that the cell is properly filled with electrolyte. Venting may also be performed to release any excess gas produced during the formation process.

Sealing the Battery

Once the battery is filled with the appropriate electrolyte and any excess gas has been vented, the next step is sealing the battery. The sealing process is critical for preventing electrolyte leakage and maintaining the integrity of the battery. The sealing methods may vary depending on the battery type (cylindrical, square, prismatic) and the manufacturer’s techniques.

Cylindrical Batteries

For cylindrical batteries, the open end of the cell is typically crimped or welded to seal it. This creates a hermetic seal, preventing the escape of electrolyte and ensuring the battery is airtight.

Square and Prismatic Batteries

Square and prismatic batteries are sealed using a combination of methods, including welding, adhesive bonding, and heat-sealing. These techniques are employed to achieve a secure seal that prevents electrolyte leakage and gas ingress.

Assembly process for cylindrical batteries

Assembly process for square batteries

Assembly process for prismatic batteries

Assembly process differs depending on the shape of the battery (cylindrical, square, prismatic). We can propose various machines used in the processes above according to customer requirements.

Assembly Process For Cylindrical, Square And Prismatic Batteries