Stockholm university logo, link to start page

New sustainable method facilitates recycling of Lithium-ion batteries

Developing sustainable and efficient methods for battery recycling plays an important role for today’s and future sustainable society. A newly published article by researchers of Stockholm University takes a huge step towards green recycling of spent Lithium-ion (LIBs) batteries.

World’s energy storage systems have been changing throughout the years. Lithium-ion batteries, LIBs dominate the market for energy storage for applications such as electric vehicles or electronics. 

When considering the cost of a single battery, the cathode takes the bigger portion with the most widely used lithium nickel manganese cobalt oxide, NMC as active material. 
Consequently, NMC cathodes and as such cobalt deserve special attention among the other constituents of a LIB cell. 
 

Green MOF
Green metal-organic framework, MOF, separates cobalt and nickel ions in the batteries.
Illustration: Bruno Vinicius Manzolli Rodrigues.

In a newly published article in ACS Sustainable Chemistry & Engineering, researchers from the Department of Materials and Environmental Chemistry, MMK, of Stockholm University reveal intriguing properties of the metal-organic framework for the separation of nickel and cobalt. Both elements are the key components for NMC cathodes in LIBs. Therefore, an important part of a recycling process is the separation of cobalt and nickel ions in the batteries. 

“We discovered that the bioinspired metal−organic framework, MOF, only adsorbs on its surface nickel ions whereas cobalt ions remain in solutions. This paves the way for sustainable recycling of LIBs at room temperature while ensuring nearly zero-carbon-dioxide emissions, says Jędrzej Piątek, PhD student at MMK and the main author of the article.

Co-author Bruno Rodrigues emphasizes that the reported method for separating cobalt and nickel gives a very high purity grade of the recovered cobalt of over 99 per cent. 

The group of Assistant Professor Adam Slabon at MMK, works on developing sustainable systems for spent LIBs recycling. 

“It is highly important for the future of our planet to minimize the harsh conditions and use of toxic chemicals in the industrial processes. Our goal is to invent methods, which will enable the implementation of circular recycling economy”, says Adam Slabon. 

Adam Slabon
Adam Slabon, Assistant Professor at MMK, Stockholm University. Photograph: Ewelina Czermak-Slabon.


The metal-organic framework in the process was based on the chemical element bismuth. This was prepared in an environmentally friendly process, using non-toxic chemicals in a method that was synthesized recently at Ken Inge at MMK. 

“Our collaboration is a demonstration how you can combine green materials for sustainable applications.”, says Ken Inge.
Future work at MMK aims at the sustainable recycling of lithium using green chemistry as tool. 

Background 

More than 60 percent of the global cobalt production reaches the market from mining operations in the Democratic Republic of Congo. This relates to an estimated annual production capacity of 3.6 million metric tons in 2019. The need to recovery valuable materials from spent LIBs is also high due to the depletion of natural deposits of metals. Conventional industrial processes still do not implement sustainable methods and involve high-temperature processes and usage of toxic chemicals. In addition, current recycling processes one does not achieve same purity grade as the starting materials for the synthesis of active electrode materials. 
This work was financially supported by the Stiftelsen Olle Engkvist (project no. 198-0329).

The research is recently published in the journal ACS Sustainable Chemistry & Engineering. 

Link to the study: Toward Sustainable Li-Ion Battery Recycling: Green Metal–Organic Framework as a Molecular Sieve for the Selective Separation of Cobalt and Nickel