Lithium-ion batteries: storage, life cycle and recycling

Lithium batteries have been on the market for half a century and are known to have a large energy capacity, which makes them long-lasting. Moreover, they can be stored for a long time in an inactive state without losing their charge.  

But despite these advantages, there was a need for another type of battery. The main disadvantage of traditional lithium batteries is that we can only use them once. Once they are used, they cannot be recharged. Therefore, in 1991, the lithium-ion battery was introduced, with a different composition and therefore with a number of modified properties.  

Lithium-ion batteries have a secondary cell construction (as opposed to the primary one of lithium batteries). As a result, they often do not last as long with single use, but they can be charged frequently. This makes lithium-ion batteries ideal for devices that use a lot of energy and therefore require regular charging, such as laptops, smartphones and now, increasingly, all kinds of electric vehicles.

Lithium-ion batteries sometimes need to be stored for a while, for example when they are waiting to be transported. This calls for a number of safety considerations.

One of the biggest concerns of both distributors and users of lithium-ion batteries is how long they actually last. It is difficult to give a definite answer, as lifespan depends on many different factors, but averages can give us an idea.

An average battery in an electric car has a service life of about 8 years. (Also read: ‘What is the lifespan of an electric car battery?’.) Most manufacturers guarantee that the average capacity will not decrease more than 20% over the 8-year period, but they hope for a longer average lifespan of 10-12 years.

In smaller devices, such as smartphones and laptops, you often see signs of battery wear earlier. Smartphone batteries can already have a reduced capacity after one year. 

What can you do to extend the life of lithium-ion batteries?

• Avoid high temperatures. Long exposure to heat reduces battery life.

• Never fully charge the battery and make sure it is not completely discharged. Do not go above 90% or below 20%. The fully charged (100%) and completely used (0%) states put more pressure on the battery. Fortunately, a so-called buffer capacity (link in Dutch) is usually pre-programmed into the (internal) battery charger, which automatically prevents excessive pressure on the battery.

• Avoid frequent fast-charging. There are more and more fast-charging points for electric cars. This is useful for those who have to travel long distances and recharge on the way, but the high voltage puts more strain on the battery. There are more and more fast-charging points for electric cars. Sometimes the manufacturer recommends to set the charger to maximum 80%, in order to use a smaller part of the battery and make it last longer.

If you work with lithium-ion batteries and are concerned about sustainability, it is interesting to know exactly how they are recycled and which raw materials are recovered from them. Here it is also important to mention that lithium-ion batteries are actually one big family with different siblings, aunts and uncles, and lithium is the common factor, but the other battery components can differ completely in quantity and even in kind and type. For example, most lithium-ion batteries on the market today have much less cobalt than before, or no cobalt at all. For a recycling company, the exact content and the potential value also determine to a large extent the price it will ask from the supplier of the batteries to be recycled. 

Depending on the company that recycles the batteries, the recycling process may look slightly different, but in general we can distinguish three main steps.

At this stage of 'mechanical processing', iron, copper foil, aluminium foil, the separator and the coating materials are extracted, but further refinement is required through pyro- and hydrometallurgy.

Pyrometallurgy: The recycling company extracts the transition metals from the battery, such as nickel, cobalt and copper, by liquefying the battery components at a high temperature. Lithium and aluminium remain in the slag. Further (costly) steps are required to recover lithium.  

Hydrometallurgy: The recycling company recovers pure metals through a process involving chemical solvents. 

Each recycling company has its own unique process. Some use both methods in combination with the mechanical processing from the first step, while others use only one. The approach they choose depends on the materials they wish to recover and the recycling efficiency they want to achieve. 

Often one recycling company does the first step and the residual materials are sent on to other recycling companies for further processing and decomposition.