Atık lityum iyon pillerdeki değerli metallerin derin ötektik çözelti kullanılarak kapalı kap mikrodalga liç prosesi ile geri kazanımı
Recovery of valuable metals from waste lithium-ion batteries using deep eutectic solvent via closed-vessel microwave leaching process
- Tez No: 964917
- Danışmanlar: DR. ÖĞR. ÜYESİ HASAN ALGÜL
- Tez Türü: Yüksek Lisans
- Konular: Metalurji Mühendisliği, Mühendislik Bilimleri, Metallurgical Engineering, Engineering Sciences
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2025
- Dil: Türkçe
- Üniversite: Sakarya Üniversitesi
- Enstitü: Fen Bilimleri Enstitüsü
- Ana Bilim Dalı: Metalurji ve Malzeme Mühendisliği Ana Bilim Dalı
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 124
Özet
Lityum-iyon bataryaların bir türü olan NMC pil (LiNixCoyMn1-x-yO2) lityum esaslı katotta nikel, mangan ve kobalt metallerinin varlığını göstermektedir. Elektrikli mobilite dünya çapında önemli ölçüde artarak çeşitli pil türlerine özellikle NMC pillere olan talebi artırmıştır. NMC pillerine olan tabelin artmasıyla doğru orantılı olarak NMC malzeme atığı miktarı da artacaktır. NMC pillerin kullanım ömürlerinin sonunda yüksek bir atık akışı meydana gelecektir. Lityum-iyon piller kobalt, nikel gibi ağır metaller içerdikleri için atık olarak çevresel endişelere neden olmaktadır. Sonuç olarak depolama alanı atıklarını en aza indirmek, insan sağlığı ve ekosistemler üzerindeki olumsuz etkilerini azaltmak için NMC pillerinden malzeme geri kazanımı sağlanmalıdır. Lityum-iyon pillerin geri dönüşümünde pirometalurji, biyometalurji ve hidrometalurji olmak üzere üç farklı teknik kullanılmaktadır. Hidrometalurjik yöntemler, mikrodalga ile desteklenerek ve derin ötektik çözücüler (DES) kullanılarak liç işlemlerinin daha kısa sürede, yüksek verimde ve çevre dostu olarak gerçekleştirilmesini ve metal kazanımını sağlamaktadır. Mevcut literatürde DES tabanlı çözücülerle lityum iyon pillerin geri kazanımı üzerine çeşitli çalışmalar mevcut olmakla birlikte bu çözücülerin mikrodalga destekli sistemlerle birlikte kullanımı henüz sınırlı sayıda araştırmaya konu olmuştur. Yapılan çalışmalar genellikle LiCoO₂ tipi piller üzerine yoğunlaşmış olup NMC katot malzemelerinin mikrodalga destekli DES liçiyle geri kazanımına dair çalışmalar oldukça sınırlıdır. Özellikle kapalı kap sistemlerde mikrodalga enerjisiyle birlikte kolin klorür/oksalik asit dihidrat çözücüsü kullanılarak NMC bileşenlerinin çözünme mekanizmalarının incelenmesi literatürde önemli bir boşluğu dolduracaktır. Bu tez çalışması, DES kullanarak kapalı kap mikrodalga destekli liç yöntemini NMC tipi atık pillerin geri kazanımında uygulayarak literatürdeki bu boşluğu doldurmayı ve çevre dostu, ekonomik bir süreç geliştirmeyi hedeflemektedir. Bu tez çalışmasında, kullanım ömrünü tamamlamış NMC tipi lityum-iyon pillerden değerli metallerin çevre dostu ve sürdürülebilir bir yaklaşımla geri kazanımında kolin klorür-oksalik asit dihidrat temelli derin ötektik çözücü kullanılarak kapalı kap mikrodalga destekli liç yöntemi uygulanmıştır. Sıcaklık, katı/sıvı oranı, süre gibi parametrelerin liç verimliliği üzerindeki etkisi incelenerek işlem parametreleri optimize edilmiştir ve sürecin uygulanabilirliği değerlendirilmiştir.
Özet (Çeviri)
Lithium-ion batteries (LIBs) are widely used in portable electronic devices, electric vehicles (EVs) and renewable energy storage systems due to their high energy densities, long cycle lives and high efficiencies. A lithium-ion battery consists of two electrodes (a cathode and an anode), a separator placed between these electrodes, an electrolyte solution absorbed by the separator, a binder typically containing about 4% polyvinylidene fluoride (PVDF) and a cell casing that encloses all these components. Among these, the cathode plays the most critical role in determining the energy density of LIBs. The battery's capacity, voltage, cycle life, safety and thermal stability largely depend on the type of cathode material used. The composition of the cathode directly impacts the battery's environmental footprint, life-cycle, and cost. Cathode materials can be economically recovered through sustainable recycling methods. Additionally, since cathodes contain metals such as cobalt, nickel, and manganese which are of strategic importance and high commercial value they represent the most valuable component in terms of recycling. Commonly used active cathode materials include LiCoO₂ (LCO), LiNiO₂ (LNO), LiMn₂O₄ (LMO) and LiNiMnCoO₂ (NMC). Among different LIB types, nickel–manganese–cobalt oxide (NMC, LiNiₓCoᵧMn₁₋ₓ₋ᵧO₂) batteries are gaining increasing attention due to their balanced electrochemical performance, relatively high capacities, and thermal stability. European countries especially Italy, France, and Germany are the primary consumers of NMC batteries for EVs, with Italy alone accounting for over 25% of total usage. The Asia-Pacific and North American regions are also experiencing significant growth in EV demand, resulting in a global 115.66% increase in demand for NMC batteries from 2021 to 2022. With the accelerating global transition toward electric mobility, the demand for NMC batteries is expected to rise substantially. In parallel, the number of end-of-life batteries will also increase, leading to urgent concerns regarding resource scarcity, environmental pollution, and the need for sustainable waste management strategies. Recycling of NMC materials is particularly important, as NMC cathodes contain expensive and scarce metals, making them the most valuable components in spent LIBs for profitable recovery. Spent NMC batteries contain various elements including 5–7 wt % Li, 5–20 wt % Co, 5–20 wt % Ni, and 5–20 wt % Mn with high recycling value, making the recovery of valuable resources from used NMC both economically beneficial and environmentally sustainable. NMC batteries have high production costs attributed to the use of less abundant and geopolitically sensitive metals such as nickel and cobalt. The scarcity of these materials not only raises the cost of NMC batteries but also exposes them to risks stemming from disruptions in global supply chain systems, affecting price stability. Thus, challenges may arise from the increasing costs of cobalt and nickel. While NMC batteries will continue to play a key role in high-energy applications, challenges related to the cost and supply of raw materials such as cobalt and nickel persist. Regulations concerning raw material supply and the scarcity of these metals may also affect the cost and availability of NMC batteries. Therefore, the recovery of metals from spent batteries is becoming crucial not only to ensure the availability of strategically critical raw materials but also to reduce battery production costs. The pre-treatment stage, which is the first step in the LIB recycling process, aims to safely and efficiently separate the battery's complex components, prevent hazardous accidents during disassembly, reduce waste volume, concentrate valuable components, and establish a solid foundation for subsequent recovery steps. Pte-treatment typically includes discharge, disassembly, separation, pyrolysis, and the separation of cathode/anode materials. Since end-of-life LIBs may still carry residual energy, they must first be safely discharged. During disassembly and separation, battery packs are dismantled, the external casing is removed, modules are separated, and access to individual cells is provided. After disassembly, separating cathode and anode materials from their respective current collectors is a critical prerequisite for recycling. Cathode materials are usually tightly bound to aluminum current collectors using PVDF binders, making direct separation difficult. Therefore, pyrolysis at temperatures above 400°C is applied to decompose PVDF and detach the cathode material from the aluminum foil. After pre-treatment, electrode materials are collected as an intermediate product known as cathode powder, which contains valuable metals such as Co, Mn, Ni, and Li. This active cathode material is subsequently processed for the extraction, recovery, and reuse of valuable metals. There are three main approaches to LIB recycling: pyrometallurgy, biometallurgy, and hydrometallurgy. Biometallurgical processes employ bacteria to dissolve metals and offer advantages such as high yields and low environmental pollution. However, cultivating high-yield bacterial strains is complex, and the process conditions are challenging. Despite low energy consumption and high metal recovery efficiency, the large-scale applicability of this method in LIB recycling is limited due to long culture durations, strict environmental requirements for microbial growth, and low production rates. Pyrometallurgical processes involve smelting at temperatures above 1400°C and suffer from severe disadvantages such as high energy consumption and cost. Furthermore, the emission of harmful gases like CO, SOₓ, NOₓ and fluorinated hydrocarbons leads to secondary air pollution. Some metals also remain in the slag, reducing recovery efficiency. Additional separation processes often involving hydrometallurgy are typically required to obtain pure materials. Among these methods, hydrometallurgical processes stand out as the most promising due to their relatively low energy requirements, high metal recovery efficiencies, and moderate operating conditions. In this method, active cathode materials are subjected to leaching in aqueous solutions containing acids or other chemical agents. Leaching agents selectively dissolve metals such as Li, Co, Ni, and Cu from battery components. After leaching, the mixture containing dissolved metals, residues, and insoluble matter undergoes solid–liquid separation. Commonly used leaching agents include inorganic acids such as H₂SO₄, HNO₃ and HCl, which offer high solubility and ease of access. However, they pose environmental and health hazards and produce toxic gases. Despite their high efficiency, traditional acid leaching methods are polluting, hazardous, and costly. In recent years, there has been growing interest in developing environmentally friendly hydrometallurgical techniques that do not rely on strong mineral acids or toxic solvents. One of the most significant innovations in this area is the use of deep eutectic solvents (DESs) as green alternative leaching agents. DESs are unique solvents formed by complexation of a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA), which melt at temperatures significantly lower than those of their individual components. Their low volatility, non-flammability, biodegradability, and ease of preparation make them attractive for sustainable hydrometallurgical applications. In particular, choline chloride (ChCl)-based DESs, when combined with organic acids like oxalic acid dihydrate, have shown great potential for the selective and efficient dissolution of metals from spent LIB cathodes. Organic acid-based DESs offer extremely high leaching efficiencies for active cathode materials, dissolving metals such as Li, Ni, Co and Mn almost entirely under moderate conditions. Moreover, since organic acids are easily degradable in nature, their environmental impact is reduced. These DESs can serve as both leaching and precipitation agents efficiently dissolving cathode materials while eliminating the need for additional precipitants. Additionally, the leaching solution obtained after metal separation can be reused, reducing the cost of LIB recycling. In the leaching and separation stages, the ChCl-OA (choline chloride–oxalic acid) DES acts as both a solvent and a precipitant, offering a high-efficiency and environmentally friendly metal recovery process. Recent studies have confirmed that DESs are suitable for recovering lithium, cobalt and nickel from LIBs. However, although DESs can enhance metal dissolution kinetics, leaching processes based solely on DESs are often time-consuming. To overcome this limitation, combining DES-based hydrometallurgical processes with microwave-assisted heating has emerged as a promising strategy. Traditional DES leaching processes generally require harsh conditions, long durations, and high temperatures. However, when supported by auxiliary techniques such as microwave irradiation, leaching efficiency can be significantly improved and process durations shortened. In recent years, microwave heating technology has found broad application due to its ability to heat materials rapidly and uniformly. DESs can effectively absorb microwave energy and convert it into heat, enhancing process efficiency and saving energy. Therefore, microwave-assisted leaching is highly suitable for recovering metals from spent LIBs. This method can be applied using open or closed vessel systems. Closed-vessel microwave systems, in particular, provide high pressure and temperature conditions that accelerate leaching reactions and enable more efficient metal recovery. Most existing studies have focused on LiCoO₂-type batteries, while research on the recovery of NMC cathode materials using microwave-assisted DES leaching remains limited. This study aims to fill this gap by investigating the leaching behavior of NMC-type cathode materials under microwave-assisted, closed-vessel conditions using a choline chloride–oxalic acid dihydrate DES. The primary objective is to develop an environmentally friendly, energy-efficient, and scalable process for the recovery of critical metals from spent NMC batteries. This thesis focuses on understanding the dissolution mechanisms of Ni, Mn, Co and Li in the DES medium under microwave energy and optimizing the key process parameters affecting metal recovery efficiency. Within the scope of this research, spent NMC-type lithium-ion batteries were disassembled, and the active cathode material was separated and characterized. A DES composed of choline chloride and oxalic acid dihydrate in specific molar ratios was prepared and used as the leaching medium. The structure of the choline chloride–oxalic acid dihydrate DES was examined via viscosity measurements, FT-IR, ¹H-NMR, and DSC analyses. The effects of parameters such as temperature, solid-to-liquid ratio and time on leaching efficiency were investigated to optimize the process and evaluate its feasibility. Leaching efficiency was assessed by analyzing the concentrations of dissolved metals (Li, Ni, Co) in the leachate using atomic absorption spectroscopy (AAS). The selectivity of the DES system for metals under different conditions was also evaluated. Morphological and structural changes in the solid residues after leaching were examined using SEM-EDS and XRD analyses to elucidate dissolution pathways. The results reveal that microwave-assisted leaching with choline chloride-oxalic acid-based DES shows high recycling efficiency in significantly shorter time than conventional leaching. This indicates that the method could serve as a sustainable and viable solution for the recovery of critical metals from NMC-type lithium-ion batteries. In conclusion, the integration of deep eutectic solvents and microwave-assisted leaching in a closed-vessel system represents a promising green chemistry approach for LIB recycling. This study provides valuable contributions to the optimization and mechanistic understanding of DES-based microwave-assisted hydrometallurgical processes for NMC cathode materials. The developed process not only enhances metal recovery efficiency and environmental compatibility but also serves as a roadmap for future industrial applications and scale-up efforts.
Benzer Tezler
- Kullanılmış lityum iyon pillerdeki metalik değerlerin mekanokimyasal yöntemle geri kazanımı
Recovery of metal values from spent lithium-ion batteries by mechanochemical process
AYÇA SÖNMEZ
Yüksek Lisans
Türkçe
2023
Metalurji Mühendisliğiİstanbul Üniversitesi-CerrahpaşaMetalurji ve Malzeme Mühendisliği Ana Bilim Dalı
DR. ÖĞR. ÜYESİ MERT ZORAĞA
- Atık lityum iyon pil katot malzemesinin anyonik yüzey aktif madde kullanarak akım toplayıcıdan ayrılması
Separation of waste lithium-ion battery cathode material from current collector using anionic surfactant
MUHAMMED EMİN ŞEYİB
Yüksek Lisans
Türkçe
2023
Kimya MühendisliğiAtatürk ÜniversitesiKimya Mühendisliği Ana Bilim Dalı
DOÇ. DR. HAKAN TEMÜR
- Investigation of separation and recovery of cobalt from end-of-life lithium-ion battery by hydrometallurgical approach
Ömrü sonlanmış lityum-iyon pilden kobaltın ayırılması ve geri kazanılmasının hidrometalürjik yaklaşımla incelenmesi
SEVDE RANA GÜNAL
Yüksek Lisans
İngilizce
2024
Mühendislik Bilimleriİstanbul Teknik ÜniversitesiMalzeme Bilimi ve Mühendisliği Ana Bilim Dalı
PROF. DR. SERVET İBRAHİM TİMUR
- Recovery of valuable metals from waste lithium-ion batteries by metallurgical routes
Atık lı̇tyum-ı̇yon pı̇llerden değerlı̇ metallerı̇n metalurjı̇k yollarla gerı̇ kazanımı
SEPEHR ABTAHI
Yüksek Lisans
İngilizce
2023
Metalurji Mühendisliğiİstanbul Teknik ÜniversitesiMetalurji ve Malzeme Mühendisliği Ana Bilim Dalı
PROF. DR. ONURALP YÜCEL
- E-atıklardan ve lityum pil atıklarından kritik metallerin kazanımı
Recovery of critical metals from e-waste and lithium battery waste
İSMAİL AĞCASULU
Doktora
Türkçe
2024
Maden Mühendisliği ve MadencilikSüleyman Demirel ÜniversitesiMaden Mühendisliği Ana Bilim Dalı
PROF. DR. ATA UTKU AKÇIL