Aluminium

Used in electrical busbars, cell cases, module housings and for pack cases. Hence a number of different grades of aluminium based on the requirements from electrical resistance, thermal conductivity, strength and corrosion resistance.

Busbars

Tesla Model Y 4680 Busbar

Electrical grade aluminum busbar material also known as ec grade aluminum busbar.

Compared to copper busbars aluminium offers a weight and cost save, but requires an increase in cross-sectional area of ~62%. Hence aluminium busbars need more volume for packaging.

Cooling Plates

The weight, machinability and thermal properties make aluminium one of the most common cooling plate materials.

Current Collector

The cathode current collector in a lithium-ion cell is made from aluminium.

Pack Structure

Made from aluminium for optimum weight and strength.


1000 series

  • 99% or higher purity
  • excellent corrosion resistance
  • high thermal conductivity
  • high electrical conductivity
  • excellent workability

downside

  • low mechanical properties

1060

  • Used as a battery busbar material.
  • Good corrosion resistance.
  • High electrical conductivity
  • Typically formed by extrusion or rolling.
  • Good workability.

downside

  • Low strength.

1100

  • Used as a battery busbar material.
  • Minimum of 99.0% aluminium.
  • Highest mechanical strength of 1000 series.
  • Excellent forming properties, especially in the fully soft, annealed temper.
  • Good thermal conductivity, hence often used in heat exchangers and heat sinks.

1350

  • Used as a battery busbar material.
  • Nearly pure aluminium with minimum weight percentage of 99.5% of aluminium.
  • Very good electrical conductivity.
  • Very good thermal conductivity.
  • Excellent corrosion resistance.
  • Tight controls are used on certain impurities that could adversely affect conductivity.

downside

  • Low mechanical strength.
  • Non-heat treatable

2000 series

  • principal alloying element is copper
  • heat treated mechanical properties can exceed mild steel

downside

  • solution heat treatment required to get optimum properties
  • corrosion resistance not as good as other aluminium alloys
  • tend to be brittle
  • exhibit poorer corrosion resistance than other alloy series.

2011

  • free machining

3000

  • principal alloying element is manganese – up to 1.5%
  • moderate strength
  • higher manganese alloys have good machinability
  • particularly resistant to pitting corrosion.

4000

  • principal alloying element is silicon, in significant amounts it lowers the melting point
  • used in welding and brazing
  • most alloys non-heat treatable
  • good casting qualities

5000

  • principal alloying element is magnesium
  • alloys with high magnesium and manganese result in high strength but non-heat treatable
  • good welding characteristics
  • anodize well
  • good resistance to corrosion even in marine environments

downside

  • limited cold working
  • lower safe operating temperatures due to magnesium content

6000

  • principal alloys silicon and magnesium
  • heat treatable
  • good formability
  • good corrosion resistance
  • medium strength
  • relatively easy to roll extrude and forge.

6063

  • Used as a battery busbar material.
  • magnesium and silicon as the alloying elements
  • good mechanical properties
  • heat treatable
  • weldable
  • good electrical conductivity
  • good bending properties

6082

  • easy to machine
  • medium strength alloy
  • excellent corrosion resistance

6101

  • Used as a battery busbar material.
  • Contains magnesium and silicon for high mechanical strength without significant reduction in conductivity.
  • Higher yield strength than 1350
  • Better creep resistance than 1350

6262

  • free machining

7000

  • principal alloy is Zinc
  • addition of magnesium results in heat-treatable and very high strength
  • sometimes other elements added such as copper and chromium

7075

  • good resistance to aggressive atmospheres

8000

  • may contain tin, iron or silicon
  • can be rolled to thin sheets