A praise, for a moment, for the anode, as it is often ignored. When the battery is powered up, lithium ions rush towards this positively charged end and accumulate there until power is needed. Originally, the anode was made of lithium metal. But lithium metal is unstable and has the potential to explode when exposed to air or water, so the scientists tried carbon instead. Over the years, they have refined it into a material consisting of hexagonal rings of atoms — a crystal lattice that can hold an infinite number of ions, without causing an explosion. That material is graphite, the same thing found on the tip of a #2 pencil. It’s often said that the cathode – that’s the other end of the battery – is where the magic happens. This is where the arrangement of metals like cobalt, nickel and manganese comes in. But each of those metals is negotiable, depending on the specific battery design. The humble graphite does not. It helps determine how much energy the battery can hold and how fast it charges.
And if the anode itself is omitted, so is its carbon footprint. As with other battery materials, automakers rely on estimates to determine the environmental costs of graphite’s globe-spanning journey before it ends up inside cars. But a number of recent studies have shown that those estimates are outdated and regrettably undercounted, not including the energy-intensive processes required to produce modern, anodic-ready graphite. . Those poor estimates are eroding efforts to clean up the supply chain for electric vehicles. “The same thing keeps repeating itself,” said Robert Pell, CEO of Minviro, a consulting firm that works with electric car companies on environmental assessments. “Everybody cares about the cathode, but the reality is that we know the impact of the anode is greatly underestimated.”
In general, electric vehicles are greener than gas-powered vehicles. Plugging them in creates emissions because it hits a dirty grid, but overall, the grid is getting greener, and electricity usage is already so much better than exploding gallons after a year. gallons of gasoline. It is the raw material for batteries that are more difficult to decarbonise. The cathode actually has the greatest environmental consequences – including carbon emissions and the ecological and human rights harms caused by mining minerals such as lithium, nickel, and cobalt. In some cases, car companies have tried remove their dependence on cobalt and nickel by swapping them for other metals.
But graphite shouldn’t pass, says Pell, an author of one of two studies. The results shed light on how companies measure their carbon footprint, especially the key component of “Scope 3.” It is often the largest, all-encompassing portion of energy that a company does not directly consume. For an automaker, that includes the carbon emitted from the vast supply chain that produces components, including batteries, and the carbon involved in putting energy into the charging cable. But it’s hard to get the goods. Go back deep enough into the supply chain, back into the raw material handling, and the specifics get fuzzy, the real power demand gets fuzzy.
This is especially true for graphite. The second study, published earlier this year by researchers at the Technical Universities of Braunschweig and Volkswagen, includes a range of assumptions and caveats found in previous estimates of carbon-graphite emissions. Some of the most common references used to calculate climate impacts derive details from old manufacturing manuals and borrow consequences from machining other materials, such as aluminum. Others simply estimate for other carbon-based materials, and do not affect the unique intensive refining steps required to rearrange the atoms into graphite.
Pell’s research began by jotting down some calculations on the back of the envelope. It helps to know that more than 90% of the graphite for the anode comes from China and largely from the northern region of Inner Mongolia, where energy is cheap but largely dependent on coal-fired power plants. Knowing the approximate carbon intensity of the power source, he began to map out the difficult steps to turn that graphite into an anode.
