What Are Alloys of Aluminum Foil Battery

The current technical level of aluminum foil battery has entered the "ultra-thin, high-precision" stage. The thickness of mainstream power battery aluminum foil is concentrated in 12-16 microns (μm), while the consumer electronics field has achieved a breakthrough of 6-9μm.

In terms of performance indicators, the tensile strength of 15μm aluminum foil jumbo roll can reach 200-210MPa, the elongation is 1.5%-4.0%, the surface roughness is controlled at Ra≤0.3μm, and the pinhole density is ≤0.5/m².

The alloy selection of battery aluminum foil needs to take into account conductivity, corrosion resistance and processing performance. Currently, three major mainstream systems have been formed:

8 series alloys (8011/8021/8079)

8011: Contains 0.8% Fe+Si, has both cost and performance advantages, is widely used in consumer electronics and energy storage batteries, and has a thickness range of 10-20μm.

8021: The Fe content is increased to 1.0%-1.5%, and the corrosion resistance is enhanced. It has become the first choice for soft-pack battery aluminum-plastic film, and the thickness can reach 0.02-0.5mm.

8079: Add 0.8% Zn, higher strength (tensile strength ≥220MPa), used for high-rate power batteries.

1 Series Pure Aluminum (1100/1235)

1100 aluminum foil: 99.0% purity, excellent conductivity (conductivity ≥ 62% IACS), but low strength (tensile strength 150-180MPa), suitable for weight-sensitive power batteries.

1235: 99.35% purity, elongation up to 5%, commonly used in carbon-coated aluminum foil for energy storage batteries.

Composite current collector

By depositing a metal layer on the PET substrate through the evaporation process, the battery energy density is increased by 20% and the risk of thermal runaway is reduced by 90%.

It is worth noting that energy storage batteries have higher requirements for the high temperature resistance of aluminum foil, and usually need to pass the 180℃/2 hour baking test. Power batteries are more concerned about thickness tolerance (±0.3μm) and density consistency (±0.85g/m²).

Market structure and future trends

Capacity and demand

The global demand for battery aluminum foil is expected to reach 600,000-1 million tons in 2025, but the actual production capacity is only 737,600 tons due to the low yield rate (average 60%), with a gap of 257,900 tons. China accounts for 70% of the global production capacity.

Technology iteration direction

Thinner: The demand for aluminum foil below 10μm will increase from 10% in 2023 to 20% in 2025, but it will put forward higher requirements for rolling mill precision and process control.

Compounding: Composite aluminum foil is expected to achieve large-scale mass production in 2025, and the localization of evaporation equipment will drive costs down by 30%.

Functionalization: Graphene-coated aluminum foil can improve the low-temperature performance of batteries (-20℃ discharge capacity retention rate ≥85%), while fluorocarbon spraying technology enhances corrosion resistance.

Haomei Aluminum mainly provides 1xxx battery aluminum foil like 1100, 1235, 1060, 1070,etc. Welcome to inquire what you need from us.