Slot Die Slurry Temperature Control for Uniform Electrode Coating

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Solution Overview

Problem

The distribution of coating loading levels in the coating process of secondary battery electrodes is challenging due to temperature changes in the active material slurry, leading to difficulties in maintaining product quality and process capability.

Innovation Solution

A slot die equipped with a temperature controller, including heating wires and cooling water lines, is used to control the temperature of the slurry in the cavity, with temperature sensors to monitor and adjust the slurry temperature, ensuring a stable and homogeneous distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the slurry temperature is not controlled during the coating process, then the coating process is simple, but the coating loading level distribution becomes uneven due to temperature changes

Engineering Contradiction:
Improvecoating loading level distributionVSAvoidtemperature control system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by controlling the temperature of the slurry during the coating process. A temperature controller adjusts the temperature parameter of the slurry to maintain it within a specific range (20-40°C), which prevents viscosity changes and ensures uniform coating loading level distribution. This directly addresses the technical contradiction by modifying the temperature parameter to improve coating precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback control through a temperature sensor that continuously monitors the slurry temperature and provides feedback to the temperature controller. The controller adjusts the heating or cooling based on the temperature feedback, ensuring the slurry remains at the optimal temperature range. This feedback mechanism resolves the contradiction by automatically maintaining coating precision without requiring complex manual intervention.

Inventive Principle:
Principle #23Feedback

2Reliability

If the slurry temperature changes during coating, then no additional equipment is needed, but the viscosity changes causing flow characteristic variations and quality issues

Engineering Contradiction:
Improveprocess capabilityVSAvoidtemperature control apparatus
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent maintains process reliability by controlling the temperature parameter of the slurry within a specific range (20-40°C). The temperature controller adjusts this parameter to prevent viscosity changes that would otherwise cause flow characteristic variations. This parameter control ensures consistent coating quality and maintains process capability throughout operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies beforehand cushioning by using heating wires and cooling water lines pre-installed in the slot die to prevent temperature fluctuations before they affect the coating process. The temperature controller anticipates and counteracts potential temperature changes by actively heating or cooling the slurry, ensuring viscosity and flow characteristics remain stable throughout the coating operation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Manufacturing precision

If process factors like pump RPM or die gap width are adjusted to reduce coating distribution issues, then temporary improvement is achieved, but process capability deteriorates during long or short period operation

Engineering Contradiction:
Improvecoating loading level uniformityVSAvoidprocess capability stability
Core Design Contradiction:
Manufacturing precisionVSDuration of action of moving object

Solution Approach 1:

The patent fundamentally resolves the issue by controlling the temperature parameter of the slurry, which directly affects viscosity and flow characteristics. By maintaining temperature within 20-40°C, the system achieves consistent coating uniformity without needing to adjust other process factors like pump RPM or die gap width. This temperature parameter control ensures process capability remains stable over both short and long operational periods.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements continuous feedback control through temperature sensors that monitor slurry temperature and provide real-time feedback to the temperature controller. This automatic adjustment mechanism ensures coating precision is maintained consistently over time without the process capability deterioration that occurs with temporary adjustments to pump speed or die gap. The feedback system adapts to maintain optimal conditions throughout extended operation.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution effectively maintains the slurry temperature, reducing variations and improving the quality and processibility of coated electrode plates by preventing deviations in coating loading levels.

Implementation Method 1

the temperature controller may include a plurality of heating wires and a plurality of cooling water lines under the cavity

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the temperature controller may include a plurality of heating wires and a plurality of cooling water lines under the cavity

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the plurality of heating wires and the plurality of cooling water lines may be alternately arranged

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

a temperature sensor configured to measure the temperature of the slurry

Methodology Applied
Scientific EffectThermal radiation detection: Thermal Radiation

Data Source

PatentEP4703049A1Slot die and apparatus and method of controlling temperature of the slot die
Publication Date: 2026.03.04 SAMSUNG SDI CO LTD
  • EP4703049A1 patent drawingFigure 1A
  • EP4703049A1 patent drawingFigure 1B
  • EP4703049A1 patent drawingFigure 1C

AI summary

A slot die includes: an upper die (110); a lower die (120) having a cavity (140), a gap being formed between the upper die (110) and the lower die (120); a slurry supply unit (130, 131, 132) connected to an external slurry supply source, the cavity (140) being connected to the slurry supply unit (130); a temperature controller (190) configured to control a temperature of a slurry in the cavity (140); and a temperature sensor (180) configured to measure the temperature of the slurry. A slot (150) is formed by the gap, is connected to the cavity (140), and is configured to emit the slurry onto a base material.