At a time when pollution, climate change, and green energy are making headlines virtually on a daily basis, it’s not surprising that solar systems are becoming increasingly popular. Currently, mainly four types of batteries are used to power residential solar systems:
– Lead-acid batteries are still by far the most common
– Flow batteries
– Nickel-based batteries
– The new kid on the block: lithium-ion solar batteries
In this article, we will focus on lithium-ion batteries, their pros and cons, and how easy or difficult it is to recycle them.
Lithium-ion batteries
As electric vehicles started becoming increasingly popular, solar manufacturers soon began to realize that lithium-ion batteries are a viable alternative solution for their energy storage needs. And it didn’t take many years for these batteries to establish themselves firmly in the solar battery market.
Right now, lead-acid batteries are still the main source of energy storage in the solar industry though. But their lithium-Iron counterparts are catching up fast. One of the reasons is that the latter needs virtually no regular maintenance. They also feature better battery energy density, i.e. they are able to store more energy in the same space than their lead-acid counterparts.
Lithium-ion solar batteries also have a longer lifespan than lead-acid ones. In fact, most of them come with a 10-year warranty compared to the three to five years of the average lead-acid solar battery.
What are the cons of lithium-ion batteries?
One of the biggest drawbacks of this type of battery is its relatively high cost. The situation will most likely improve as the use of lithium-ion in solar batteries increase and the market becomes more competitive.
Lithium-ion solar batteries also have a relatively high chance of catching fire. But if they are installed properly, the likelihood of this happening is very close to nil.
Recycling lithium-ion solar batteries
Not unlike recycling solar panels, it’s relatively complex and costly to separate the different components of a lithium-ion battery so they are ready to be recycled and reused again. Although there are facilities for recycling these batteries, they are not nearly on the same scale as their lead-acid counterparts. At the moment it is estimated that only around 5% of these batteries are recycled. Taking into account the increasing popularity of lithium-ion batteries in the solar industry, it is imperative that the scale and efficiency of these recycling facilities are improved.
The lithium-ion solar battery recycling process
The first step is to freeze the lithium-ion batteries to -321°F by using liquid nitrogen. This is to prevent explosion or combustion during the shredding process. The next step involves cleaning off the flammable electrolyte. After that, the cathode material can be recovered.
Mainly two kinds of technologies are used during the recovery and recycling of these batteries.
Hydro-metallurgical (chemical processing). This involves the cathode material being subjected to a chemical process that separates the individual compounds. That makes it possible to purify them. The next step involves either chemically altering them into different compounds or refining them. It is, e.g., possible to recover lithium compounds, treat them, and then sell them as lithium hydroxide or lithium carbonate – both of which are core inputs in the manufacturing of new lithium-ion batteries.
Furnace processing. With this technique, the metals are recovered after first removing impurities via a slag-like process. Unfortunately, however,, the lithium compounds also get captured in the process, and removing them from the ‘slag’ is by no means a cheap process.
Final thoughts
It is certainly not a brilliant idea for highly flammable lithium-ion batteries to be stored in warehouses across the US and then forgetting about them. A much better alternative is probably to include the cost of recycling in the original purchase price.
Sources:
https://www.solarreviews.com/blog/types-of-solar-batteries#lithium-ion-batteries
http://blog.veolianorthamerica.com/how-to-recycle-solar-panels-lithium-batteries-and-electronics
https://www.solarpowerworldonline.com/2019/10/a-qa-on-battery-recycling/
https://news.energysage.com/lithium-ion-battery-recycling/
https://simplysolarcalifornia.com/are-solar-batteries-recyclable/
https://insideenergy.africa/is-recycling-lithium-ion-batteries-possible/
