Soft-Pack EV Cell Manufacturer – In-Line Carbon/Sulfur Quality Control

1. Market Background

With the rapid growth of the electric vehicle industry in Asia, soft-pack lithium batteries with high energy density are becoming a core focus for battery manufacturers. For these cells, even trace levels of carbon and sulfur impurities in raw materials can:

• Increase internal resistance and accelerate capacity fade;

• Generate unwanted gases and by-products, affecting safety and cell consistency;

• Make it harder to meet OEMs’ strict quality and reliability requirements.

As a result, fast and accurate carbon and sulfur determination has become a key part of process control for high-energy-density soft-pack cells.

2. Customer & Application Scenario

The customer is a soft-pack EV cell manufacturer, mainly supplying automotive OEMs. Its production lines require:

• Batch-by-batch inspection of cathode and anode materials;

• Faster internal testing to match production takt time;

• More transparent and traceable impurity control to satisfy customer audits.

Before upgrading, the customer relied partially on external labs and older analysis equipment, which led to:

• Long testing cycles and delayed material release;

• Limited capability to correlate carbon/sulfur data with process changes;

• Difficulty demonstrating robust impurity control during OEM audits.

The customer learned about Wuxi Qianrong Instrument Co., Ltd. and its high-frequency infrared carbon and sulfur analyzer for lithium battery applications at the 3rd High Energy Density Soft-Pack Lithium Battery Development Forum in Changzhou.

3. Our Solution

Based on the customer’s EV cell production needs, Wuxi Qianrong Instrument Co., Ltd. provided a high-frequency infrared carbon and sulfur analysis solution tailored to lithium battery materials:

• Instrument Configuration

  • A high-frequency infrared carbon and sulfur analyzer configured for lithium battery cathode and anode materials, metallic components and related new energy materials.

  • Method setup optimized for typical battery materials to ensure repeatable results.

• Application Coverage

  • Incoming inspection: batch-wise carbon/sulfur testing for cathode materials.

  • In-process monitoring: regular checks on anode materials and conductive additives.

  • Pre-shipment verification: random testing of critical metallic parts and materials before release.

• Workflow Integration

  • Design of a sampling and preparation workflow that aligns with the cell plant’s takt time.

  • Integration of test results into the customer’s internal quality system for traceability and data trending.

4. Customer Feedback

After several months of operation, the customer reported:

1. Stable and Reliable Data

   • Carbon and sulfur test results showed good repeatability across batches, providing a solid basis for material evaluation and supplier management.

2. Shorter Material Release Cycle

   • Compared with relying on external testing, in-house analysis with the high-frequency infrared carbon and sulfur analyzer significantly shortened the raw material release time, helping to reduce inventory bottlenecks.

3. Stronger Position in OEM Audits

   • During EV OEM audits, the customer was able to demonstrate a dedicated carbon/sulfur control capability for lithium battery materials, improving overall quality recognition.