At the heart of the electric vehicle revolution, the battery stands as the cornerstone of this ecological transformation. Historically, the advent of the battery dates back to the 19ᵉ century, but it is in recent decades that we have witnessed a meteoric evolution, propelled by the climate emergency and the quest for sustainable mobility.
In this context, electric vehicle batteries are not just reservoirs of energy; they embody the hope of a future that is less polluting and more respectful of our environment. Today, several types of battery have been developed, each with its own specific features, advantages and disadvantages, making the choice of the right technology crucial for manufacturers and consumers alike.
This comprehensive guide invites you to delve into the world of electric vehicle batteries, detailing the types and characteristics of the technologies currently available on the European market.
Nickel-Cobalt-Aluminium (NCA) and Nickel-Manganese-Cobalt (NMC) batteries
Nickel-Cobalt-Aluminium (NCA) and Nickel-Manganese-Cobalt (NMC) batteries are among the predominant choices for high-performance electric vehicles such as the Tesla Model S and Model X (with NCA batteries) or the BMW iX3 and Volvo EX30 (with NMC batteries). Known for their high energy density, these batteries facilitate longer range and faster charging, essential criteria for end-users, as shown by the EV user profile study we carried out last year. Increased range and the development of fast-charging infrastructures make long electric car journeys easier.
Composition and functioning
NCA and NMC batteries are variants of lithium-ion batteries. They use cobalt in their cathodes, a key element that gives these batteries superior energy density and robust thermal capacity. Cobalt also serves to stabilize the cathode structure, prolonging battery life.
The benefits
- High energy density: these batteries deliver longer range on a single charge, a critical factor in the adoption of electric vehicles.
- High performance: NCA and NMC batteries deliver outstanding performance, even at high temperatures, making them ideal for sporty vehicles.
Disadvantages
- Cost: cobalt is an expensive material, and its extraction is often tainted by ethical issues, particularly with regard to child labor and working conditions in the mines.
- Environmental impact: cobalt mining also poses environmental challenges, particularly in terms of pollution and waste management.
Lithium-Iron-Phosphate Batteries(LFP)
Lithium-iron-phosphate (LFP) batteries are distinguished by their chemical stability and relatively low cost. With no cobalt in their composition, they represent a more durable and economical alternative to NCA and NMC batteries.
Composition and functioning
LFP batteries use lithium iron phosphate as the cathode. This chemical composition gives the battery thermal and chemical robustness, reducing the risk of overheating and fire.
The benefits
- Durability: LFP batteries have a longer life and do not suffer from the memory effect, making them ideal for applications requiring frequent charging cycles.
- Lower cost: the absence of expensive metals like cobalt and nickel makes these batteries cheaper to produce.
- Safety: the chemical stability of LFP batteries reduces the risk of fire and explosion.
Disadvantages
- Lower energy density: compared with NCA and NMC batteries, LFP batteries offer lower energy density, which translates into reduced range.
- Sensitivity to cold: the performance of LFP batteries can be affected by very low temperatures, limiting their effectiveness in certain climatic conditions.
Nickel-Metal Hydride (NiMH) batteries
Nickel-Metal Hydride (NiMH) batteries have long been a reliable option for electric and hybrid vehicles, offering a good balance between cost, performance and environmental friendliness. Although supplanted in some areas by newer technologies, they remain relevant in certain applications.
Composition and functioning
NiMH batteries feature a metal hydride anode and a nickel oxyhydroxide cathode. They operate on the principle of hydrogen ion exchange between the electrodes, enabling energy to be stored and released efficiently.
The benefits
- Environmental impact: NiMH batteries contain no toxic heavy metals, making them more environmentally friendly than other battery types.
- Cost: Although not the cheapest, NiMH batteries are competitively priced, not least because of the abundance of materials used.
- Durability: NiMH batteries are renowned for their long life and ability to withstand a large number of charge and discharge cycles.
Disadvantages
- Energy density: compared with Li-ion batteries, NiMH batteries have a lower energy density, which can limit the range of electric vehicles.
- Weight and volume: NiMH batteries are generally heavier and bulkier than Li-ion batteries, which can affect vehicle performance and design.
Sodium-ion batteries, a real alternative to lithium-ion batteries
Sodium-ion batteries are emerging as a promising alternative to traditional lithium-ion batteries. Sodium, which is abundant and less expensive than lithium, offers an opportunity to cut costs while preserving performance.
Composition and functioning
Sodium-ion batteries work on the same principle as lithium-ion batteries, but use sodium ions instead of lithium ions. This substitution takes advantage of the abundance and availability of sodium, thus reducing production costs.
The benefits
- Lower costs: sodium is much more abundant than lithium, making sodium-ion batteries cheaper to produce.
- Reduced environmental impact: sodium extraction and processing generally have a lower environmental impact than lithium.
- Low-temperature performance: sodium-ion batteries deliver good performance even in low-temperature conditions.
Disadvantages
- Energy density: although promising, sodium-ion batteries have a lower energy density than lithium-ion batteries, which can affect the range of electric vehicles.
- Ongoing development: as with solid-state batteries, sodium-ion battery technology is still in the development and maturation phase. The first EV models have just been equipped with this technology.
Solid and semi-solid batteries
Solid-state and semi-solid-state batteries represent a major advance in the field of batteries for electric vehicles. By replacing the liquid electrolyte with a solid, these batteries promise increased energy density, improved safety and longer life.
Unlike traditional lithium-ion batteries, which use a liquid electrolyte, solid and semi-solid batteries employ a solid material to enable the movement of ions. This feature eliminates the risk of leakage and reduces the likelihood of fire, offering a safer solution.
However, this technology will only be deployed by 2030, according to BMW, which is working on these battery models.
When should solid-state batteries reach the market?
Solid-state batteries should be deployed by 2030, according to BMW, which is working on these battery models, or sooner, as they suggest in the video below?
Summary table
To make things clearer, here is a summary table of the different types of batteries for electric vehicles, showing their main characteristics:
Main picture : Powertrain and battery of theTesla Model S
