Abstract
The growing demand for energy storage devices due to the skyrocketing production/consumption of portable electrical and electronic equipment as well as electric vehicles has promoted battery technologies, resulting in the piling of a large number of waste lithium-ion batteries (LIBs). Organic binders wrapped on electrode particles are usually the main reason that causes the difficulty of liberation and extraction of electrode materials. Pyrolysis or incineration is the general approach to separate the organic binder, leading to fluorinated exhaust gas emissions. In this study, the supercritical carbon dioxide (SC CO2) combined with a cosolvent dimethyl sulfoxide was innovatively adapted to enable the extraction of organic binders from spent LIBs to facilitate the liberation of the cathode material from aluminum foil. Pure polyvinylidene fluoride was preferentially used to study the SC CO2 dissolution mechanism. The results indicate that 98.5 wt% polyvinylidene fluoride (PVDF) dissolves in SC CO2 dimethyl sulfoxide system under the optimum conditions; 70°C process temperature, 80 bar pressure, and 13 min duration. After removing PVDF, the recovered sample was characterized by Fourier Transform Infrared Spectrometer (FTIR) and thermogravimetric analyzer (TGA) to observe its possible re-utilization. It is clear that the surficial chemical groups and content remained the same after treatment. SC CO2 processing effectively liberates the active cathode material from the aluminum substrate due to removal of the binder. The suggested innovative approach is promising as an alternative pretreatment method due to its high efficiency, relatively low energy consumption, and environmentally friendly features.
Highlights
The gradual popularity of consumer electronics and electric vehicles initiate a transaction in portable energy storage devices that lithium-ion batteries (LIBs) gradually became a kind of major power source due to the preferable electrochemical characteristic and relatively long service-life (Shin et al, 2005, Ramanayaka et al, 2020)
Supercritical CO2 combined with a cosolvent dimethyl sulfoxide (DMSO) was adapted to extract polyvinylidene fluoride (PVDF) binders from spent LIBs cathodes and facilitate the liberation of the cathode material from aluminum foil
The experimental results indicate that 98.5 wt% pure PVDF was dissolved using a supercritical CO2- DMSO system under the optimum conditions of 70◦C temperature, 80 bar pressure, and 13 min process time
Summary
The gradual popularity of consumer electronics and electric vehicles initiate a transaction in portable energy storage devices that LIBs gradually became a kind of major power source due to the preferable electrochemical characteristic and relatively long service-life (Shin et al, 2005, Ramanayaka et al, 2020). Existing technologies to achieve the liberation between the electrode material and aluminum/copper foils are mechanical crushing (Ku et al, 2016, Zhang et al, 2013), ultrasonic cleaning (Li et al, 2009), organic solvent dissolution (Xin et al, 2016, Nayaka et al, 2016), and high temperature processes (Hao et al, 2014, Choi and Kim, 2012) These methods were technically sufficient to remove the PVDF binder and liberate the electrode active materials from the substrate. Research on the recycling of transition metals and organic chemicals from waste LIBs by supercritical carbon dioxide (SC CO2) technology has become increasingly attractive due to its unique ness to minimize the hazardous effects of the recovery process to the environment (Lv et al, 2018). Actual cathode material was used to propose a recycling process for spent LIBs with lower chemical consumption and needed operation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
