Li-Cycle, a Canadian cleantech company founded in 2016, uses Spoke & Hub Technology that allows for the recycling of all types of lithium-ion batteries with a high recovery rate of up to 95% of the materials. The battery recycling process is designed to be safe, scalable, and sustainable, addressing the growing demand for battery recycling as the global electrification movement accelerates.
Challenges: lithium battery recycling
The rapid growth of electric vehicles has a significant impact on the demand for Li-ion batteries. By 2030, it is anticipated that 140 million electric vehicles will be on the roads worldwide, while 11 million metric tons of Li-ion batteries will reach the end of their service lives. Currently, most used Li-ion batteries are discharged in landfills, and less than 5% of batteries are recycled.
A typical lithium-ion battery has four key components:
- Cathode: containing different formulations of lithium metal oxides and lithium iron phosphate depending on battery application and manufacturer, intercalated on a cathode backing foil/current collector (e.g. aluminum)—for example: LiNixMnyCozO2; LiCoO2 ; LiFePO4; LiMn2O4; LiNi0.8Co0.15Al0.05O2;
- Anode: generally containing graphite intercalated on an anode backing foil/current collector (such as copper);
- Electrolyte: for example, lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate monohydrate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(bistrifluoromethanesulphonyl) (LiTFSI), lithium organoborates, or lithium fluoroalkylphosphates dissolved in an organic solvent (e.g., mixtures of alkyl carbonates, e.g. C1-C6 alkyl carbonates such as ethylene carbonate (generally required as part of the mixture for sufficient negative electrode/anode passivation), ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, propylene carbonate); and
- Separator between the cathode and anode: for example, polymer or ceramic based.
Thus, materials found in lithium-ion batteries therefore include organics, iron, aluminum, copper, plastics, graphite, cobalt, nickel, manganese, and lithium. It is estimated that more than 11 million tonnes of spent battery packs contain approximately US$65 billion of residual value in metals and other components.
In addition, recycling lithium-ion batteries could reduce greenhouse gas emissions by approximately 1.2 billion equivalent tonnes of CO2 between 2017 and 2040 by offsetting/reducing the amount of raw material derived from primary sources (i.e. mining, refining) and preventing the landfilling of metals (e.g., heavy metals) and materials from spent lithium-ion batteries.
Thus, recovering materials from spent Li-ion batteries is highly desirable.
Pyrometallurgy is a fire process to recover valuable metals from waste lithium ion batteries. The pyrogenic process burns the organic binder in the electrode material by high-temperature incineration at near 1500 °C and then obtains the metal compound through flotation, precipitation and similar techniques.
However, the current pyrogenic recovery process burns the volatile organic compounds and generates a large quantity of acid corrosive gasses (such as HF and PF), which causes more severe secondary pollution and can cause great harm to human bodies and the environment. To treat harmful emissions, sophisticated equipment is needed, which raises the capex cost. Today, several large pyrometallurgy facilities recycle Li-ion batteries, recovering cobalt, nickel, and copper but not lithium, aluminum, or any organic compounds.
Hydrometallurgy processing or chemical leaching is a less energy-intensive and less capital-intensive alternative. These processes for extracting and separating cathode metals typically run below 100 °C and can recover lithium, copper, and other transition metals. The requirement for caustic reagents (such as hydrochloric, nitric, and sulfuric acids and hydrogen peroxide) is a drawback of traditional leaching techniques.
Li-Cycle Technology
Li-Cycle developed Spoke-Hub recycling technologies for Li-ion batteries. The Spoke technology involves the mechanical reduction in size of incoming used batteries in a safe manner. Hub technology involves the hydrometallurgical recycling and resource recovery methods designed specifically for recycling lithium-ion batteries. Li-Cycle’s Spoke-Hub technology can recycle at least 95% of all materials found in used Li-ion batteries.
Li-Cycle Spoke-Hub technology
The diagram below depicts the Spoke-Hub technology.
The Spoke: a safe size reduction technology
The Spoke facility is capable of recycling both large format lithium-ion batteries (e.g. automotive, energy storage system battery packs) and small format lithium-ion batteries (e.g. from laptops, mobile phones, tablets, etc.). Batteries entering these facilities are first discharged to inert objects, and then undergo a mechanical safe size reduction process that renders them suitable for further processing. The Spoke technology comprises the subsequent procedures: