Copper is a critical material in the manufacturing of all vehicles, regardless of whether they are powered by gas, diesel, electricity, hydrogen, or even liquid natural gas (LNG). The demand for copper from the automotive industry was just over 3MT (1MT = 1 billion kilograms) in 2023 but is set to increase to 5MT in 2034.
Today’s vehicles already contain lots of copper, used predominantly in the wiring. Cars have grown larger and more complex over the decades, which has caused their wiring requirements to explode from a handful of connections to thousands. The wiring harness is now a sprawling labyrinth, spanning literal miles throughout the car. And the weight from these miles of cables adds up. The wiring harness is one of the single heaviest components of a vehicle, with some vehicles having harnesses in excess of 60kg and containing an average of approximately 25kg of copper.
Cars are continuing to grow more complex, requiring even more wiring. And, despite Tesla and others working towards a simplified, optimized, and more efficient vehicle networking, IDTechEx predicts that the wiring harness will continue to grow over the coming years. However, the additional copper required for the ever-growing wire harness is dwarfed by the new copper demand generated through electrification.
Building an electric powertrain requires many copper-hungry components that were previously not needed for internal combustion engine vehicles. The traction motors, high voltage cabling, inverter, and charger require in the region of 10-15kg. The motor is the determining factor in this range, with factors like having single or dual motors and the motors design having a large impact on the copper required. However, the copper demand for these individual components is still small compared to the battery. IDTechEx’s research finds that the average 64kWh battery in a fully electric car requires 25.4kg of copper.
Copper’s electrical and chemical properties mean that it is used throughout the battery. Every single cell within the battery, of which there are hundreds or thousands, contains a copper foil to carry power out of the cell. Additionally, there are large copper bars throughout the battery carrying the power from all the cells out of the battery and transferring it to the high voltage cables and eventually the power electronics and motor.
Of course, copper is not the only element capable of fulfilling these tasks, but in most instances, its physical, electrical, and chemical properties that make the most sense. Aluminium is a common candidate to replace copper. It is about one-third of the price of copper and is less dense and, therefore, typically lighter than copper. Aluminium has seen some uptake in busbars and wiring, with Tesla being one of the big-name adopters. However, this only represents around 10-20% of the copper content in the battery, with the rest being the foils in the cells.
Copper foil is only used on the cathode side, and due to the way aluminum interacts with lithium on the negative terminal of the battery, it cannot be used here. Likewise, copper would dissolve if it was used as a current collector at the anode. There are other materials that could replace copper at the cathode, such as stainless steel, carbon/graphite, and titanium, but these have issues around their cost, weight, and conductivity, which means adoption is very unlikely.
So, with copper foil being the only reasonable choice as a current, is there anything that can slow its growing demand? IDTechEx finds that there are a couple of mechanisms that reduce the amount of copper needed per kilowatt hour of battery capacity. The first is moving to thinner foil sheets. Today’s standard copper foil thickness is 10µm, but IDTechEx has seen companies working on foils with thicknesses of 6µm and below. The other factor that impacts copper intensity is battery chemistry.
Battery chemistry is one of the biggest factors governing how much energy a cell can store. Assuming that everything else remains the same, such as material thicknesses and cell form factor, then if chemistry A has double the energy of chemistry B, batteries made with chemistry A will have half the copper of batteries with chemistry B for the same overall energy capacity. In reality, this is not far off the situation with the leading battery chemistries – NMC and LFP. IDTechEx’s research found that the average copper intensity in kg/kWh of an LFP cell was nearly double that of an NMC cell.
Other chemistries are available and have their place in electrification, but for the automotive market over the next 10 years, IDTechEx predicts that LFP and NMC will dominate, accounting for more than 90% of the market between them. LFP will likely grow its market share between now and then thanks to its good-enough energy density and lower prices compared to NMC. This will cause a corresponding increase in copper demand for electric vehicles, as coupled with LFP’s higher copper intensity, IDTechEx also expects average battery sizes per vehicle to increase.
