Electric car batteries — the material facts

Neelesh Vasistha Feb 1, 2021 · 5 min read

Pens out. Let’s talk about a little miracle of chemistry. Inside a battery, in a part known as the anode, you’ll find a swarm of restless electrons. They want nothing more than to visit somewhere else: the cathode. These two areas, however, are separated by a cushion of electrolyte. But once you place the battery into a closed circuit, the electrons see a path to their beloved anode, and promptly rush toward it. This chemical love story of cathodes and anodes is significant — it’s the basis of battery power. Along their journey to the anode, these electrons discharge energy to anything in the circuit; your phone, your remote control, or on a massive scale; your electric car.

Living in a material world

A battery’s materials determine its capacity, output and, well, usefulness. For this reason, the makeup of batteries have been experimented with for decades.

The batteries in many early EVs were made from lead acid, two words that hardly inspire an image of clean modernity. While lead acid is still around, mostly in traditional cars, most people associate EV batteries with one metal in particular: lithium. It makes a great battery for several reasons. It’s dense, which in battery lingo means it offers a high storage capacity compared to its size or weight. Indeed, compared to the lead-acid batteries of yore, lithium batteries are around ten times denser. This, of course, is helpful when moving heavy objects like cars. Lithium’s chemical profile also makes it very reactive, allowing a current to gush from anode to cathode. Finally, because electrons in lithium batteries slide easily back into place, lithium is a ‘very’ rechargeable material.

Because of their importance to vehicle performance and costs, the EV world celebrates developments in battery technology. One company recently produced lithium batteries that can be fully charged within five minutes, although this requires a much higher-powered charger than those used today. There is also often chatter of the ‘holy grail’ that is the solid-state battery — offering a much denser battery at less weight. But until then, lithium-ion technology today represents a happy compromise between capacity, volume and mass.

But lithium, despite its battery stardom, needs one or more sidekicks. By adding transition metals to lithium, its attributes as a battery are enhanced. In most modern EV batteries, the cathode contains either cobalt, nickel or manganese. Nickel, for example, can make up to 80% of an EV battery’s cathode. As a battery material it has played a background role in the digital revolution, used first in the digital cameras and power tools of the 1980’s, before jumping inside smartphones. Its advantage is delivering higher energy density and greater storage capacity at a lower cost. This density also helps to extend vehicle range.

Cobalt is also dense, allowing batteries to pack more energy in smaller spaces, making them lightweight and powerful at the same time. In addition, its ability to survive high temperatures boosts the safety and reliability of the car. Finally, promotes a more sustainable supply chain in that it increases the life of batteries while being highly recyclable.

Manganese, the second most common component in batteries by volume and weight, is often used in place of cobalt. It makes the anode in batteries, for which there is no substitute. Manganese’s flat voltage profile allows full power to be used until the battery is discharged. Because it’s so cheap, this material could hold the key to lowering battery (and thus EV) costs.

Source of the problem

The electric car revolution is in full swing, creating a commercial impetus for bigger and better batteries. But to meet rising demand, more metals must be sourced. This creates a knot of ethical and sustainability problems. The problem here is that much of the world’s reserves of valuable materials for EV batteries lie within troubled parts of the world. Creating a global supply chain means docking with unestablished or openly corrupt nations.

One acute concern is human rights. The worst example is the DRC, which contains half of the world’s lithium reserves, and 40% of the world’s untapped cobalt. But the means of extracting and processing cobalt paints a grim picture. Some estimate there are more than 40,000 children working in the DRC’s artisanal cobalt mines with little concern for safety, let alone the illegality of child labor. Another issue is environmental degradation in the name of profit. In Chile, part of the ‘Lithium Triangle’ alongside Argentina and Bolivia, lithium mining has crowded out the agricultural sector, and contributed to soil contamination.

Government bodies are uniting with manufacturers to tackle these looming concerns. The OECD and EU, for example, have established guidelines to enforce the traceability of mined materials. At Chargetrip, we hope initiatives like this will help ensure transparency and dignity across global supply chains.

In the electric car revolution, countries are helped or hindered by the quantity of geological resources that happen to fall within their borders. The ability, or inability to source raw materials locally decides the production power of national battery industries, placing manufacturing nations into a political chess match. China and the US, for example, are both superpowers of metal, both producing and importing large amounts, whereas the U.K is practically barren, and thus reliant on the tides of global trade.

The road ahead

Batteries power electric vehicles, which in turn help power the green revolution. This makes them the subject of intense industry and media interest. While lithium seems to be the star player, it needs field support from other materials. There is no doubt that developers will continue tinkering with known and experimental materials in order to create lighter and more powerful batteries. Sourcing these, however, raises uncomfortable questions, as mineral extraction forces unlikely partnerships between established and unestablished nations. While the road ahead for electric cars is exciting, there is still much paving to be done.

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