With the rapid development of the electric vehicle industry, lithium batteries, as the core power source, have increasingly strict requirements for production processes. Electrode coating, as a crucial step in the production, its uniformity and consistency directly affect the energy density, safety performance and cycle life of the batteries. In this precise manufacturing process, piezo actuators, with their unique technical advantages, became one of the core components that can achieve ultra-high-precision coating control.

Lithium battery electrode coating refers to the process of evenly coating the prepared electrode slurry (positive or negative electrode material) on the surface of metal foil (aluminum foil or copper foil). After going through subsequent processes such as drying, these slurries will form electrode sheets. This step is like dressing the lithium battery in a uniform energy coat, laying the foundation for the subsequent charging and discharging process. The core purpose of coating is to enable the electrode material to adhere evenly and stably to the substrate, thereby ensuring the efficient conversion and storage of electrical energy during the charging and discharging process of lithium batteries. The uniformity of coating, thickness consistency and edge neatness directly determine the characteristics of the battery:

1. Energy density:The more uniform the coating, the more stable the battery capacity and performance.

2. Safety:Coating defects may lead to local overheating or even thermal runaway.

3. Cycle life:Large fluctuations in coating thickness can easily cause accelerated aging of the battery.

(Note: Image from online resources)

Especially batteries for electric vehicles, the electrode length can be up to hundreds of meters. Any slight coating deviation may lead to a decline in the performance of the entire batch of batteries or even their scrapping. Therefore, there are extremely high requirements for the coating process: precision, speed and response.

Three core requirements for the coating process of lithium batteries:

1.Thickness control:The thickness tolerance of the electrode slurry coating must be controlled within an extremely small range; otherwise, it will lead to uneven current distribution inside the lithium battery, affecting the battery capacity and cycle life.

2.Good stability:The coating process should be continuously stable to avoid missed or over-coated areas.

3.Dynamic response:During high-speed operation, it is necessary to be able to promptly adjust the position of the coating scraper or coating head to compensate for other interferences.

(Note: Image from online resources)

The low-voltage cylindrical piezo actuator is highly suitable for integration. Its exterior is protected by a cylindrical stainless steel casing, and a preload force is applied to the piezo stack through a mechanical housing. The high internal mechanical preload force can be applied to high-load and high-dynamic applications. CoreMorrow low-voltage cylindrical piezo actuator can provide nanometer-level resolution, millisecond-level response time, and travel up to 190 μm.

Characteristics

•   Nanoscale resolution

•   Optional closed-loop sensor

•   Travel to 190μm

•   Blocking force to 25000N

•   Outer diameter, height and displacement all on request

Technical Data

Note: The length, diameter, pins and interface of the piezo actuator can all be customized as required.

VT14 and VT17 preloaded piezo actuator with anti-torque design can effectively eliminate a certain amount of torsion in the process of mounting or others, and effectively protects the internal piezo stack from direct action, avoiding damage to the ceramics. It is compact in structure and very easy to integrate.

Characteristics

•  Withstand torque, special mechanical housing

•  Max displacement to 95μm

•  Blocking force 1200N

•  Sub-millimeter response time

Technical Data

High voltage cylindrical preloaded piezo actuators is a cylindrical piezo stack with mechanical preload and driving voltage of 1000V. It could withstand some certain pulling force, built-in piezo stack with large blocking force up to 50000N, mainly used for dynamic applications of large loads.

Characteristics

•   1000V driving

•   Stroke to 260μm

•   Load capacity to 70000N

•   Open/closed loop

•   Customizable

•   Outer diameter Ø18mm, Ø25mm, Ø35mm, Ø45mm

Technical Data