160 years after French physicist Gaston Planté invented the rechargeable lead- battery, technologies to store energy via electro-chemical processes have made immense progress. All the scientific work has had a similar goal: to find the best possible compromise between the battery’s weight, storage capacity, production costs, lifespan, recharging capacity and environmental impact, especially when the time comes for it to be recycled.
Invented in 1859, the lead-acid battery is still found in many vehicles, those with both combustion and electric engines. In 1899, the electric vehicle “La Jamais contente” (“The Never Happy”) featuring this technology was in fact the first automobile to exceed 100 km/h, well before combustion engine vehicles.
These days, lead-acid batteries are no longer used for traction, but to power the electrical circuit of accessories or components specific to combustion engines like the starter. The lead-acid battery only offers a limited capacity despite its significant bulk and weight, but it has the advantage of being both inexpensive and easy to produce and recycle. Used as the main energy storage mechanism for electric cars right up until the 80s, it quickly gave way to other, more efficient technologies.
If you used rechargeable batteries in the 90s, then you’re already familiar with nickel-cadmium technology. “Ni-Cd” accumulators had plenty of advantages, with significant storage density and a lifespan of around of 500 to 1,000 charging cycles.
However, they did suffer from memory effect, a physical phenomenon that sees the battery’s performance decline if it is subject to partial “charge-drain” cycles. Used for the production of electric vehicles in the 90s, Ni-Cd batteries are now prohibited due to the toxicity of cadmium.
With performance similar to Ni-Cd technology, nickel-metal hydride (Ni-MH) accumulators have seen longer success due to their absence of heavy metals. This portable rechargeable battery technology was the most economical at the beginning of the 2000s, which is why it largely dominated the hybrid vehicle market, up until the advent of lithium-ion technology.
Developed in the early 90s, the lithium-ion battery has gradually established itself as the leading technology, both in the world of transportation and in the consumer electronics industry. With a long lifespan, it offers far greater energy density than all competing technologies and is not subject to memory effect.
However, it does require suitable packaging as well as precise control of the recharging process, generally achieved via a dedicated electronic circuit. Renault uses lithium-ion technology for ZOE and the other electric vehicles in the range. Moreover, the Group is working on incorporating its batteries into a circular economy setup aiming to extend their lifespan as much as possible.
Scientific research has long been exploring the concept of the solid-state battery, but it’s only in the last 10 years that its progress has made it possible to envisage the technology’s adoption by the automotive industry in the distant future.
The principle behind it consists of replacing the battery’s liquid electrolyte with a solid material that can take the form of a plastic polymer, compacted inorganic powders or a mixture of the two. In theory, this technology is all positives: it makes it possible to increase energy density and stability while making temperature control easier. Nonetheless, the solid-state is still at the laboratory prototype stage. The lithium-ion battery still has a lot of life left in it!
Copyrights : Petrovich9, Chesky_W, Renault