Technology

How electric batteries are made

 By Nicholas Newman

The design, functionality and price of vehicle batteries are the decisive factors in any decision to invest in the mass manufacture of electric vehicles (EVs)…

Batteries are integral to the main formats of electric vehicles (EVs) namely, hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs) and all-electric vehicles (EVs). Lithium-ion batteries are the current market leader, far outweighing alternatives such as Nickel-Metal Hydride batteries, or Lead-Acid batteries and Ultra capacitors.
Electric-vehicle batteries, or traction batteries, differ from the batteries that power torches, radios or toys. For a start, they deliver greater power over a much longer period, owing to their high ampere-hour capacity, high power and energy-to-weight ratio and high energy density. However, in comparison to petrol engines, current batteries still have a limited range between recharging stops.
For instance, the Nissan Leaf, with its lithium-ion battery, has a range of just 150 miles. According to Nissan, a replacement battery for the Nissan Leaf hybrid is currently £4,920 while the list price of the cheapest Nissan Leaf retails from £21,680. At these prices, demand is depressed.
China is the market leader in lithium-ion battery production with a 55 percent market share, which is expected to rise to around 65 percent by 2021, based on mass manufacture of hybrid vehicles as a stepping stone towards EVs. Surprisingly, despite the media prominence of Elon Musk and his Giga-battery factory, the U.S. market share is just 10 percent. The traction battery market is forecast to reach $25 billion by 2020 assuming sales of 11 million hybrids and 1.5 million apiece of fully electric cars and range extenders, across China, Japan, the U.S. and western Europe.

Battery composition

The three primary components of a lithium-ion battery are the positive and negative electrodes and an electrolyte. Generally, the negative electrode is made from carbon or graphite, the positive is made from a metal oxide and the electrolyte is composed of lithium salt in an organic solvent. The electrochemical roles of the electrodes reverse between anode and cathode, depending on the direction of current flow through the cell.
Depending on composition, the voltage, energy density, life and safety of a lithium-ion battery can vary dramatically. Recently, nanotechnology has helped to improve performance and reduce the possibility of batteries catching fire.

This illustration shows the inner workings of a lithium-ion battery (Argonne National Laboratory)

Challenges to mass manufacture

Building a sufficient number of battery factories to enable a transition from internal combustion engines to electronic vehicles involves financial, logistical and technological challenges. Elon Musk’s battery operation offers an example of the scale of the challenge. The Tesla Gigafactory at Sparks Nevada, has cost $5 billion and occupies nearly 4.9 million square feet across several floors. It has an annual capacity for 35 gigawatt-hours (GWh) — one GWh being the equivalent of generating (or consuming) 1 billion watts for one hour), which is nearly as much as the entire world’s current battery production combined.

The Tesla Gigafactory (tesla.com)

In the past year, plans for 10 Giga factories have been announced, reports news wire service, greentechmedia. Accumotive, the Daimler subsidiary in Germany, has laid the foundation for a $550 million lithium-ion battery plant designed to raise annual production to 320,000 units.
Car manufacturers also need to decide between in-house battery production or outsource supplies from dedicated battery makers. If the former, car makers may need to lock-in supplies of cobalt, lithium, copper and nickel by way of contracts or by buying stakes in miners. For instance in the U.K., Nissan is making all its batteries for its Leaf range of cars at its factory near Newcastle in England.
Practical logistics are equally important for battery makers, as explained in an interview with Stephen Irish, Managing Director, Commercial Hyperdrive Innovation who says, “getting a reliable, stable supply chain, for all the constituent components, takes a lot of work. Also once the batteries are made, the logistical effort in getting them to where they need to be can be difficult, especially if the vehicle manufacturer is a long way from where the battery is made.” That is why Hyperdrive have chosen to co-locate their battery assembly facilities with the Nissan / AESC cell manufacturing sites, which have already benefited from significant investment in automation, robust supply chains and manufacturing process excellence.
There remains the up- hill technological challenge of boosting power-storage capacity to make traction batteries as good as petrol-driven engines, in terms of speed, range and price.

Production will be heavily automated inside the Tesla Gigafactory (Michael Ballaban, Jalopnik)

How is battery-building technology changing?

The operational life and productivity of batteries is being improved through battery management software. Hyperdrive have developed a platform for standard, modular battery packs with inbuilt control and communication electronics, safety systems and data logging capability. Tesla, Panasonic and Samsung have achieved cost reductions by fully automating and integrating production lines, by mass production and benefit of experience. However, the raw material costs of car batteries are anticipated to rise, if the Anglo Swiss miner, Glencore’s prediction of 31.7 million new electric car sales by 2030 is realized.

READ MORE: Powering the energy storage revolution by Mike Scott

about the author
Nicholas Newman
Freelance energy journalist and copywriter who regularly writes for AFRELEC, Economist, Energy World, EER, Petroleum Review, PGJ, E&P, Oil Review Africa, Oil Review Middle East. Shale Gas Guide. https://nicholasnewman.contently.com/