The truth about lithium battery black spots that engineers dare not ignore
>＞＞ Global engineers urgently share: the first publicized core parameters of black spot prevention and control of Ningde Times/BYD!
🛠️ Process level eradication program (domestic equipment parameters)
✅ Coating black mark eradication program
► Pilot Intelligent G16 Coater Gold Parameters:
Tension fluctuation ≤0.5N (laser real-time feedback system)
Slurry viscosity 8000±150cP (temperature control accuracy ±0.3℃)
Substrate jitter ＜2μm/m (with air-bearing guide)
✅ Lithium battery drying process China standard
► Winhope Technology DryMaster™ system real configuration:
| drying section | Temperature | air velocity | relative humidity | role |
|---|---|---|---|---|
| pre-dry | 85±1℃ | 0.8m/s | 25% | Evaporated free water |
| primary drying | 110±1℃ | 2.5m/s | ≤5% | Breaking the water bond |
| shaping segment | 65±0.5℃ | 0.3m/s | 15% | Suppression of crystallization defects |
⚗️ Electrochemical grade core breakthroughs
🔥 PC co-embedded reaction China program
► Ningde Times patent CN202310001.X:
Add 1.5-2.5% fluorinated ethylene carbonate (FEC)
Replace PC with ADN+EMC composite solvent
Black spot rate ↓ 94.2% (2025 mass production data)
❄️ Low Temperature Black Spot Terminator
► BYD Blade Battery Process:
Graphitization ＞98.5% (high temperature purification process)
Pre-lithiation compensation 8.3% active lithium (nano-silicon doping)
Electrolyte addition 0.5M LiTFSI ionic liquid
📊 Moisture control Chinese standard system
| control node | international standard | Chinese solution | Recommended domestic equipment |
|---|---|---|---|
| Drying of pole pieces | ≤200ppm(IEC) | ≤150ppm(GB) | Keheng KHD-80 Dewpoint Meter |
| Liquid injection environment | -Dew point 45°C | -50°C dew point | Gree G-HBOX Pro Glove Box |
| Seal Testing | 5×10⁻⁷ Pa·m³/s | 2×10⁻⁷ | Precision Measurement Electronics HEL-800 Helium Detector |
⚙️ Practical cases of production line
The results of technological reform of Hefei base of Guoxuan Gaoke:
Input: $42M (including win-win drying system × 6 sets)
Key Parameters:
Coating speed ↑35% → 45m/min
Drying energy consumption ↓28%
Black spot rate 1.7% → 0.08%
Payback period: 4.8 months (an industry record)
🚀 Engineer Emergency Action List
Diagnosis: Analyze black spot elemental composition using SEM-EDS coupling (immediate shutdown for Fe>500ppm)
Upgrade: Apply for Evonik DryMaster™ DEMO (send online moisture monitoring module)
Replacement: Request for sample of Nintek FEC additives (with co-embedded reaction test protocol)
⚠️ 2026 Mandatory New Regulation: IEC 62660-3 Requirement for Black Spot AI Traceability System (Non-compliance banned from European and American Markets)
