THE POSITIVES AND NEGATIVES OF EV BATTERIES

EV TECH EXPLAINED

- Tom Jervis

EV technology is definitely here to stay, but despite plug-in cars become increasingly common, the tech that powers them remains something of a mystery, with manufacturers offering very little explanation as to exactly how electricity from a plug socket is stored in your car and subsequently consumed and transformed into kinetic energy via the electric motors.

To find out more, we visited Porsche's battery development centre in Weissach, Germany, to speak to its experts and help demystify battery jargon.

HOW DO EV BATTERIES WORK?

MOST electric car batteries are of the lithium ion variety, which is essentially a much larger version of the type found in your smartphone. A battery pack comprises several different modules, which contain a variety of cells; the Porsche Taycan’s 93kWh Performance Battery Plus, for example, has 33 modules, each accommodating 12 cells.

Each cell has a positive ‘cathode’ and a negative ‘anode’; the former is made from either Lithium Nickel Manganese Cobalt Oxide (NMC) or Lithium Iron Phosphate (LFP), while the latter is usually made from graphite. These are split by a non-conductive separator, with a liquid ‘electrolyte’ solution surrounding it all, enabling lithium ions to be transferred between the positive and negative ends.

When the car is charging, lithium ions flow through the cabling and, in the case of pouch-style batteries such as the ones used by Porsche, inside via metallic tabs. These are funnelled into the anode and then, thanks to the presence of electrolytes, through the separator and into the cathode, where they are stored. When the car is discharging energy, the opposite will occur, with lithium ions travelling from the cathode to the anode and through cabling onto the electric motor.

LFP VS NMC