Recovery of positive electrode active material from spent lithium-ion battery

This thesis aims to design and develop environmentally friendly process by using mineral processing technique in liberating and concentration positive electrode active material. The original contribution to the body of knowledge is related to the unique insights into the selective liberation of lithium-ion battery (LIB) by applying cutting mill and attrition scrubbing aim at concentrating LiCoO2 particles. The current research practice often involves the use of organic solvent such as n-methyl-pyrrolidone (NMP) to dissolve the polyvinylidene fluoride (PVDF) to obtain LiCoO2 concentrate. However, the use of mechanical treatment to effectively liberate LiCoO2 is still under examined. This study is carried out by employing mineral processing techniques. The initial liberation by using only cutting mill produce selective liberation with optimum cut point of 850 µm. However, 56.3 wt% of LiCoO2 active materials are still held together by the PVDF binder and laminating the surface of the current collector in the size fraction of > 850 µm. This result suggests that the selective liberation by only using cutting mill is sub-optimum. The lack of liberation prompted the use of attrition scrubbing as a secondary stage of mechanical treatment. Attrition induces abrasion and it is shown to effectively liberate the LiCoO2 particles. The proof of concept shows 80.0 wt% LiCoO2 particles can be recovered in the size region of < 38 µm with 7.0 wt% aluminium and 6.1 wt% copper recovery, making attrition scrubbing a suitable second stage mechanical treatment for the recovery of LiCoO2 particles. The relative breakage rate between LiCoO2, copper and aluminium during attrition have also been studied. To further the discussion, parameters affecting attrition scrubbing liberation have been studied and presented. The proof of concept to further separate the attrition product have also been reported. The separation techniques involve electrostatic separation to separate copper and aluminium in the larger size fraction (> 38 µm) and froth flotation to separate the graphite from the finer size region (< 38 µm)

Recovering lithium cobalt oxide, aluminium, and copper from spent lithium-ion battery via attrition scrubbing

In this manuscript, the results show that the single-stage liberation by using a cutting mill is sub-optimum. From the analysis, that the size fraction of 850 µm size fraction. The low recovery of LiCoO2 is caused by the particles that are still adhering on to the surface of the aluminium current collector. This lack of liberation prompted the use of attrition scrubbing as a secondary stage of mechanical treatment. 2.5 min Attrition scrubbing improves the selective liberation of cobalt towards aluminium and copper by 36.6 % and 42.6 % respectively. Attrition induces abrasion and it is shown to liberate the LiCoO2 particles. Results show a minimum of 80 wt% LiCoO2 particles can be recovered in the size fraction of < 38 µm with 7.0 wt% aluminium and 6.1 wt% copper recovery, making attrition scrubbing a suitable second stage mechanical treatment for the recovery of LiCoO2

A methodology to liberate critical metals in waste solar panel

The availability of critical metals is one of the driving factor to secure the transition of energy production to a renewable, low carbon one because of the material requirement in photovoltaic technology (PV), wind power generation and batteries. For example, precious metals are vital to manufacture crystalline silicon solar panel and tellurium, germanium, indium and gallium are essential in thin film photovoltaic panels. However, the pressure on the supply of critical metals increases with the growth of photovoltaics. Considering the resource availability, the recycling of critical metals from waste solar panels can enhance the sustainability of end-of-life management, although the recycled metal input is limited in present state. Among the recycling techniques, the separation and liberation of metals from non-metals are crucial. This study investigate a methodology to liberate thin film materials from copper indium gallium selenide (CIGS) thin-film solar panel to recycle photovoltaic material including indium and gallium via a mechanical process.An experimental technique using mineral processing techniques, crushing and grinding, are proposed to recycle critical metals from CIGS solar panel. In this study, the crushing experiments were conducted and the size based elemental distribution was analysed. The results showed crushing is capable to delaminate glass substrate and Fuerstenau upgrading curves and the ore separation degree were used to show that selective liberation occurs and the critical metals concentrate in coarse size fraction but may not be fully liberated. The morphology test using SEM-EDS to observe the surface of broken panel and the classification of broken particle based on size, metal concentration and surface morphology were conducted. The results suggested that approximately 90 w% of functional materials are still laminated on EVA in the size fraction larger greater than 2360 μm. It shows crushing alone will not fully liberate the material. Grinding can be used as a second stage recycling method, de-coating the target materials. The grinding test resulted in a more than 80 w% recovery rate of indium and the fine particle less than 38 μm contains more than 1500 ppm indium, more than 480 ppm gallium and 1500 ppm molybdenum. It could show that the combination of crushing and grinding is suitable to delaminate the panel and de-coat the critical metals to liberate and concentrate the metals

Recycling of enamelled copper wire from end-of-life electric motor via room temperature methanolysis

Polyester enamelled copper wire plays an important role in the manufacturing of electric motors. In line with the electrification of transport, the demand for electric motors and the future waste generated from their end-of-life cannot be ignored. The waste from the polyester enamelled copper wire is expected to increase steadily. Methods proposed by researchers are mainly focused on thermal treatment to either pyrolyse or burn off the polyester enamel. However, thermal treatments fail to consider the potential risk of air pollution and to recover the polyester enamel. In this manuscript, we propose two-stage processes comprised of methanol washing and room temperature methanolysis with dichloromethane as co-solvent and K2CO3 as catalyst to delaminate multilayered type enamelled copper wire. The methanol washing recovers polyvinyl butyral as it is, via dissolution. Whereas the methanolysis products are dimethyl terephthalate (DMT) and dimethyl isophthalate (DMI) which are precursors to the polyester and could be used to make new polyester. At room temperature, the parameters of solid to liquid, DCM to methanol, and K2CO3 to Cu ratio, of 500 g/L, 1.00 mol/mol, and 0.10 wt%, respectively, allow complete removal of polyester enamel in 24 h. The methanolysis parameters described manage to give a modest DMT and DMI yield of 86.0% and 92.2%, respectively. The reaction time can be sped up by increasing the temperature by 10 °C, leading to complete depolymerisation in 4 h. Compared to thermal treatment, the proposed method requires 80.7% lower energy with the products contained within the solution

Selective liberation in dry milled spent lithium-ion batteries

ithium-ion batteries (LIBs) have an established role in the consumer electronics markets with minimum risk of replacement from any other contender in the near future. The recent momentum towards electric vehicles and the renewable energy storage market is creating an increased demand for LIBs. The large amount of hazardous waste generated from the disposal of LIBs is driving research into a sustainable approach for LIB treatment and recovery. The positive electrode active materials being the main targeted component as it is the greatest cost contributor to LIBs production. During the production of the positive electrode, a powder of active material typically Lithium Cobalt Oxide is applied to aluminium foil and held together using a polyvinylidene fluoride (PVDF) binder. The recovery of positive electrode active material involves physical and chemical treatment. Where effective and efficient physical treatment would reduce the cost incurred for the subsequent chemical treatment. Mechanical treatment is an integral part of liberating and concentrating positive electrode active material. The positive electrode active materials have been reported are being concentrated in the finer size region. However, the cut point at which the positive electrode active material being concentrated is substantially greater than the size of the positive electrode active material particle size as found in spent LIBs. This paper studies the characteristics of milled spent LIBs concerning particle size. The results suggest that a cut point of 850 μm gives the best composition of the positive electrode active materials recovery that minimises the involvement of copper and aluminium. However, most of the active materials are still held together by the PVDF binder that creates a substantially higher cut point proposed that the actual size of the positive electrode active material contained within spent LIBs. The interaction of copper and aluminium current collector based on size also further discussed in this paper. A comparison between selective liberation in the new and spent LIBs has been made to assess the difference in mechanical properties that contribute to its overall liberation efficiency

Recovery of positive electrode active material from spent lithium-ion battery

This thesis aims to design and develop environmentally friendly process by using mineral processing technique in liberating and concentration positive electrode active material. The original contribution to the body of knowledge is related to the unique insights into the selective liberation of lithium-ion battery (LIB) by applying cutting mill and attrition scrubbing aim at concentrating LiCoO2 particles. The current research practice often involves the use of organic solvent such as n-methyl-pyrrolidone (NMP) to dissolve the polyvinylidene fluoride (PVDF) to obtain LiCoO2 concentrate. However, the use of mechanical treatment to effectively liberate LiCoO2 is still under examined. This study is carried out by employing mineral processing techniques. The initial liberation by using only cutting mill produce selective liberation with optimum cut point of 850 µm. However, 56.3 wt% of LiCoO2 active materials are still held together by the PVDF binder and laminating the surface of the current collector in the size fraction of > 850 µm. This result suggests that the selective liberation by only using cutting mill is sub-optimum. The lack of liberation prompted the use of attrition scrubbing as a secondary stage of mechanical treatment. Attrition induces abrasion and it is shown to effectively liberate the LiCoO2 particles. The proof of concept shows 80.0 wt% LiCoO2 particles can be recovered in the size region of < 38 µm with 7.0 wt% aluminium and 6.1 wt% copper recovery, making attrition scrubbing a suitable second stage mechanical treatment for the recovery of LiCoO2 particles. The relative breakage rate between LiCoO2, copper and aluminium during attrition have also been studied. To further the discussion, parameters affecting attrition scrubbing liberation have been studied and presented. The proof of concept to further separate the attrition product have also been reported. The separation techniques involve electrostatic separation to separate copper and aluminium in the larger size fraction (> 38 µm) and froth flotation to separate the graphite from the finer size region (< 38 µm)

Recycling of enamelled copper wire from end-of-life electric motor via room temperature methanolysis

Polyester enamelled copper wire plays an important role in the manufacturing of electric motors. In line with the electrification of transport, the demand for electric motors and the future waste generated from their end-of-life cannot be ignored. The waste from the polyester enamelled copper wire is expected to increase steadily. Methods proposed by researchers are mainly focused on thermal treatment to either pyrolyse or burn off the polyester enamel. However, thermal treatments fail to consider the potential risk of air pollution and to recover the polyester enamel.In this manuscript, we propose two-stage processes comprised of methanol washing and room temperature methanolysis with dichloromethane as co-solvent and K2CO3 as catalyst to delaminate multilayered type enamelled copper wire. The methanol washing recovers polyvinyl butyral as it is, via dissolution. Whereas the methanolysis products are dimethyl terephthalate (DMT) and dimethyl isophthalate (DMI) which are precursors to the polyester and could be used to make new polyester. At room temperature, the parameters of solid to liquid, DCM to methanol, and K2CO3 to Cuwireratio, of 500 g/L, 1.00 mol/mol, and 0.10 wt%, respectively, allow complete removal of polyester enamel in 24 h. The methanolysis parameters described manage to give a modest DMT and DMI yield of 86.0% and 92.2%, respectively. The reaction time can be sped up by increasing the temperature by 10 °C, leading to complete depolymerisation in 4 h. Compared to thermal treatment, the proposed method requires 80.7% lower energy with the products contained within the solution