Raw Materials Selection Procedure for Battery Cell Manufacturing

Selecting the right raw materials is critical for ensuring battery safety, longevity, performance, and cost-efficiency. Here's a step-by-step guide to selecting and qualifying materials for battery cell production:

‍

1. Define Application and Performance Requirements

Begin by clearly identifying the application (e.g., EV, ESS, consumer electronics) and define key performance targets:

Energy Density
Cycle Life
Thermal Stability
Cost per kWh
Safety & Abuse Tolerance
Sustainability (e.g., cobalt-free options)

Example: For electric two-wheelers in India, LFP cathodes may be preferred over NMC due to lower cost and good thermal stability despite lower energy density.

‍

2. Choose Your Approach: R&D on Commercial vs Emerging Materials

Path	Pros	Cons	Use When...
Commercially Available Materials	Proven reliability, existing supply chain, easier qualification	May offer limited performance gains	Time-to-market is critical or for initial scale-up
Next-Gen or High-Priced Materials	Higher performance potential, future competitiveness	Uncertain scale-up, supply, or regulatory status	You have R&D capacity and aim for innovation leadership

‍Example: Tesla shifted from NCA to high-nickel cathodes after extensive in-house R&D to increase energy density and reduce cobalt use.

‍

3. Create a Selection Matrix

Criteria	Weight	Material A (LFP)	Material B (High-Ni NMC)
Energy Density	30%	7	9
Cost	25%	9	5
Safety	20%	8	6
Supply Chain Risk	15%	9	6
Regulatory/Sustainability	10%	8	5
Total Score	-	8.0	6.4

This helps in rational decision-making and aligning materials with business and technical goals.

4. Lab-Level Testing and Qualification

Once shortlisted, conduct tests in a lab setting. This includes:

Material Purity & Structure
Electrochemical Performance
Thermal Stability
Chemical Compatibility
Environmental Degradation (humidity, temperature)

Create coin or pouch cells to test materials in real-world battery configurations

5. Qualification Criteria for Manufacturing

Before moving to pilot or commercial scale, validate:

Supplier reliability (volume, consistency, documentation)
Batch-to-batch reproducibility
Compatibility with other components (binder, electrolyte, separator)
Long-term stability and aging results
Manufacturing process compatibility (e.g., calendaring behavior of electrode)

Standard References: ISO 12405 (Battery Testing), IEC 62660 (Automotive Batteries), UL 2580 (Safety)

6. Instrumentation Required for Material Evaluation

Technique	Instrument	Purpose
SEM / TEM	Scanning/Transmission Electron Microscope	Study surface morphology and particle size
XRD	X-ray Diffraction	Identify crystal structure and phase purity
XPS	X-ray Photoelectron Spectroscopy	Analyze surface chemistry and oxidation states
BET	Surface Area Analyzer	Determine porosity and surface area
TGA / DSC	Thermogravimetric Analysis / Differential Scanning Calorimetry	Assess thermal stability and decomposition
EIS	Electrochemical Impedance Spectroscopy	Evaluate resistance and ion conductivity
CV / GCD	Cyclic Voltammetry / Galvanostatic Cycling	Electrochemical performance benchmarking
ICP-OES / AAS	Trace metal analyzers	Detect metallic impurities

This helps in rational decision-making and aligning materials with business and technical goals.

7. Pilot Scale Validation

Build limited batches (e.g., 100–1000 cells) to validate:

Electrode manufacturability (slurry, coating, drying)
Cell performance (capacity, cycle life, safety)
Scaling behavior (consistency, yield rates)

Example: A European gigafactory validated a high-nickel cathode from a new supplier through pilot lines using dry electrode coating before final approval.