Lityum-iyon piller, yüksek enerji ve güç yoğunlukları, uzun çevrim ömürleri ve kendilerine özgü güvenlik özellikleri sayesinde çok çeşitli uygulamalarda enerji depolama için en önde gelen seçenek olarak öne çıkmaktadır. Bununla birlikte, lityum iyon pillerin birçok avantajına rağmen, yüksek üretim maliyetleri ve sınırlı enerji depolama kapasitesi gibi bazı dezavantajların getirdiği sorunlar hala devam etmektedir. Bu dezavantajlar, batarya performansını artırma potansiyeline sahip alternatif aktif malzemelerin önemli bir şekilde araştırılmasına yol açmaktadır. Silisyum (Si) 3579 mAh/g spesifik kapasitesi ve diğer anot aktif malzemelerine kıyasla nispeten düşük maliyeti nedeniyle büyük ilgi görmektedir. Bununla birlikte, silisyumun bir anot malzemesi olarak entegre edilmesinin getirdiği avantajların yanında, önemli hacim büyümesi ve şarj ve deşarj prosesleri sırasında yetersiz iletkenlik gibi aşılması gereken bazı dezavantajlar da bulunmaktadır. Silisyum anotların dezavantajlarının önüne geçebilmek amacıyla, araştırmacılar yenilikçi nanoyapı tasarımları gibi kapsamlı çalışmalar ve araştırmalar yapmaktadırlar. Ancak bu tasarımda silisyum hala elektrolit ile doğrudan temas etmekte ve hacim genleşmeleri için potansiyel taşımaktadır. Alternatif bir yaklaşım ise silisyumla beraber tamamlayıcı özellikler sergileyen malzemeler kullanılarak kompozit anotlar geliştirmektir. Bu tez kapsamında, silisyum anot malzemesinin, indirgenmiş grafen oksit (iGO) tabakaları arasına dekore edilerek yeni nesil pil teknolojilerine uyarlanması, yazdırılabilir yöntemler ile sunulmuştur. Çünkü ince ve esnek hücrelerinelde edilmesi için, yeni üretim tekniklerinin geliştirilmesi hayati önem taşımaktadır. Yazdırılabilir pillerin ölçeklenebilir üretimi için uygun bir üretim tekniği arayışı, serigrafi baskıyı ön plana çıkarmaktadır. Bu tercih, tekniğin doğasında var olan basitlik, hızlı işleme yetenekleri ve çeşitli alanlarda geniş uygulanabilirliğinden kaynaklanmaktadır. Si/iGO malzemeleri ile serigrafi arasındaki sinerjilerin araştırılması, bu kompozitin gelecekteki büyük ölçekli üretimini ve lityum iyon hücrelerde kullanımını etkileyebilecek potansiyele sahiptir. Serigrafi yöntemi ile üretilmiş bataryalar önemli avantajlarıyla dikkat çekmektedir. Genel olarak hafif, ince ve esnek yapılarıyla önemli avantajlar göstermektedirler. Tüm bunlara ek olarak büyük ölçekli ve uygun maliyetli süreçlerle üretilebilmeleri, günden güne gelişen enerji teknolojileri sistemleri açısından oldukça önem arz etmektedir. Bu yöntemle üretimi gerçekleştirilen pillerin performansı, başta viskozite ve yüzey gerilimi olmak üzere mürekkep özelliklerine bağlı olmaktadır. Beklenen optimum mürekkep özellikleri, bir polimer ağı içinde homojen partikül dağılımı sağlayan orta düzeyde viskozite ve minimum sedimantasyon gerektirmektedir. Baskı teknolojileri, tamamen işlevsel piller de dahil olmak üzere çeşitli pil bileşenlerini üretmedeki avantajlarını şimdiden göstermektedir. Ayrıca hem sprey baskı hem de serigrafi baskı yöntemleri vasıtasıyla, yüksek kapasiteli ve uzum çevrim ömrü gösteren grafit elektrotların başarıyla üretildiği bilinmektedir. Tez kapsamında yapılan çalışmalar, geleneksel silisyum anotlara potansiyel bir alternatif olarak İndirgenmiş Grafen Oksit (iGO) takviyeli Silisyum Anot sentezinin serigrafi yöntemi ile uygulanmasının araştırılmasına yöneliktir. Olağanüstü elektrik iletkenliği ve mekanik özellikleriyle öne çıkan grafen, silisyum esaslı anotlarda karşılaşılan zorlukların önüne geçmek için umut verici bir yol sunmaktadır. İGO'nun silisyuma entegrasyonu, hacim genişleme zorluklarını iyileştirme ve lityum-iyon pillerin termal stabilite, uzun çevrim ömrü ve enerji yoğunlukları gibi elektrokimyasal performansını artırma gibi durumlar açısından oldukça umut vadetmektedir. Tüm bunların ışığında, verimli ve hafif şarj edilebilir enerji depolama arayışında, yazdırılabilir Lityum-İyon Piller (LIB'ler) için Si/iGO kompozitlerine dayalı yeni mürekkepler araştırılmıştır. Silisyumun gösterdiği iletkenlik ve döngü kararlılığı sorunlarına karşılık, Lityum-İyon batarya performansını artırmak adına Yolk-shell (kabuklama) yöntemiyle Si/iGO yapıları sentezlenmiştir. Sentezlenen bu yapılar su bazlı anot mürekkeplerinin üretiminde kullanılmıştır. Carboxymethyl Cellulose (CMC) ve Polyethylene Oxide (PEO) bağlayıcı kullanılarak hazırlanan çözelti ile geleneksel üretim yöntemi olarak bilinen CMC ve Styrene-butadiene (SBR) bağlayıcı çözeltisi karşılaştırılmıştır. Si/iGO/CMC/PEO mürekkep tabanlı baskılı elektrotlar, hem nanokompozit sentez yönteminin hem de serigrafi baskıya dayalı geliştirilen üretim yönteminin iyi kombinasyonunun bir sonucu olarak, Si/iGO/CMC/SBR elektroduna (92,5 ohm ve 1,26 × 10-⁸ cm² s-¹) kıyasla daha düşük bir yük aktarım direnci (65,7 ohm) ve daha yüksek bir Li⁺ difüzyon katsayısı (7,83 × 10-⁸ cm² s-¹) göstermiştir. Bu özellikler Si/iGO/CMC/PEO nanokompozitini hızlı şarj ve deşarj işlemleri için daha elverişli hale getirmektedir. CMC/PEO bazlı baskılı elektrot 0,05C'de 50 döngüden sonra 2988 mAh g-1 kapasite sergilemektedir. Ayrıca, deşarj kapasitesinin korunması %89'dur. 50 şarj-deşarj döngüsü boyunca tatmin edici bir döngü kararlılığı sergileyerek anot için umut verici kapasiteler göstermiştir.
Concerns regarding climate change and the finite nature of traditional fossil fuels have necessitated a global transition toward sustainable and renewable energy sources in the modern world. The exponential growth of human activities and businesses has led to a parallel increase in energy demand, thereby driving the need for high-efficiency energy storage technologies. Among various available options, battery technology stands out as a critical enabler for the utilization of renewable energy sources and as a key technology powering a wide range of contemporary systems and devices. To meet the ever-increasing energy demands of electronic devices and the growing reliance on mobile technologies, continuous advancements are required in areas such as capacity enhancement, reduction of charging times, and extension of battery life. Lithium-ion batteries have emerged as the leading option for energy storage across a wide range of applications due to their high energy and power densities, long cycle lives, and inherent safety features. However, despite their numerous advantages, lithium-ion batteries still face challenges such as high production costs and limited energy storage capacity, which require further attention. These challenges have driven significant research efforts among scientists to explore alternative active materials with the potential to enhance battery performance. Among the most promising candidates, silicon has garnered substantial interest due to its exceptionally high specific capacity of 3579 mAh/g and relatively low cost compared to other materials. Nonetheless, the integration of silicon as an anode material presents several challenges, including significant volumetric expansion and poor conductivity during charge and discharge processes. In response to the challenges posed by silicon anodes, researchers have conducted extensive studies to address these issues through innovative nanostructure designs. A widely adopted and effective strategy involves producing composite anodes by combining silicon with materials that exhibit complementary properties. Additionally, in the pursuit of manufacturing thin and flexible batteries, screen printing has emerged as a prominent production technique for the scalable fabrication of Si/rGO (Reduced Graphene Oxide) anode materials. This preference stems from the inherent simplicity, rapid processing capabilities, and broad applicability of the technique across various domains. Investigating the synergies between Si/rGO materials and screen printing holds significant promise for uncovering key insights that could profoundly impact the large-scale production of this composite, thereby advancing battery technology to new frontiers. The development of small, flexible, and high-capacity batteries has become essential to meet the growing demands of emerging technologies, including wearable electronics, electric vehicles, and portable medical equipment. Novel battery architectures offer promising prospects for the future due to their flexibility, enhanced mobility, and improved usability, enabling them to address the requirements of advanced technologies such as wearable electronics effectively. xxii Batteries manufactured using the screen printing method have garnered attention due to their numerous advantages. They are exceptionally lightweight, thin, and flexible, all of which can be achieved through large-scale and cost-effective processes. Among numerous production techniques, screen printing stands out due to its streamlined process and high production speed. The quality of printed batteries largely depends on ink properties, particularly viscosity and surface tension. Optimal ink characteristics require moderate viscosity, ensuring homogeneous particle distribution within a polymer matrix, and minimal sedimentation. Printing technologies have already demonstrated their advantages in producing various battery components, including fully functional batteries. For instance, screen-printed cathodes containing lithium cobalt oxide (LiCoO) and lithium iron phosphate (LiFePO4) have exhibited remarkable capacities. Additionally, both spray printing and screen printing methods have successfully produced graphite electrodes with favorable electrochemical properties. Notably, a fully printed graphite/LiCoO2 battery has achieved high capacity levels, showcasing the significant potential of printing technologies to enhance battery performance and scalability. The screen printing method holds significant potential for the production of high-performance and environmentally friendly lithium-ion batteries. It offers considerable advantages, particularly due to its ease of application and its ability to significantly reduce production costs. Through this innovative approach, existing challenges are addressed while also providing insights into future requirements. This ensures the continued relevance of lithium-ion batteries as a cornerstone of sustainable energy solutions. Alongside its technical and environmental benefits, the socio-economic advantages of water-based anode inks and screen printing techniques are also of great importance. The method also provides significant advantages in terms of worker health and safety, contributing to improvements that substantially reduce the incidence of occupational diseases and injuries. These positive changes in workplace safety foster a more efficient and sustainable working environment, which can lead to higher employee satisfaction and productivity. Furthermore, the reduction of environmental pollutants, the preservation of natural ecosystems, and the protection of public health align with broader societal objectives. This, in turn, fosters a more positive societal perception of lithium-ion battery production. This situation will demonstrate the successful application of this innovative approach to Li-ion battery production and serve as an example for future advancements in this field. By encouraging further research and optimization of production techniques and environmentally friendly materials, it exemplifies a culture of sustainability and innovation within the energy storage industry. As it is adopted and further developed by researchers and manufacturers, the potential for continuous improvements in battery performance, cost-effectiveness, and environmental impact will increase. Additionally, the development of next-generation environmentally friendly technologies will continue. The forward-thinking approach mentioned is not only vital for preventing current disadvantages but also serves as a forecast for emerging future needs. This foresight is particularly important in ensuring that Li-ion batteries remain a cornerstone of sustainable energy solutions in the coming years. The adoption of the innovative techniques discussed paves the way for a greener and more sustainable future in energy storage technology, potentially revolutionizing the battery manufacturing industry. This research aims to facilitate the widespreadadoption of high-performance, environmentally friendly Li-ion batteries by addressing critical disadvantages such as safety, cost, and environmental impact. The shift toward water-based production methods is also of significant importance for societal and stakeholder engagement. Moreover, companies and organizations can leverage the environmental and safety benefits of these new processes to enhance their corporate social responsibility (CSR) profiles, potentially attracting more investment and partnerships. Local communities, in turn, may benefit from the reduced environmental hazards and improved health outcomes, fostering a more positive relationship between battery manufacturers and the communities in which they operate. In the future, advancements in screen printing techniques and water-based anode inks could influence regulatory standards and industry practices. An increasing number of institutions and companies may adopt these safer and more sustainable methods, which is crucial for the future of environmentally friendly production processes, non-toxic materials, and stricter environmental regulations. Companies will be able to maintain cost and performance advantages while aligning with new standards. This transformation could drive further innovation within the industry. In this thesis, research has been conducted on the application of Reduced Graphene Oxide (rGO)-enhanced Silicon Anode synthesis as a potential alternative to traditional silicon anodes through the screen printing method. Graphene, renowned for its high electrical conductivity and mechanical properties, presents a promising solution to overcome the challenges associated with silicon anodes. The integration of rGO into silicon holds promise for addressing issues related to volumetric expansion and enhancing the overall electrochemical performance of lithium-ion batteries. To enhance the conductivity of silicon and overcome challenges related to volumetric expansion, the superior mechanical strength and electrical conductivity of graphene have been utilized. To address the cycle stability issues encountered in silicon anodes, Si/rGO structures have been synthesized to improve battery performance. Additionally, to adapt expensive and complex traditional production techniques to a simplified screen printing method, Si/rGO composite inks were prepared, and their rheological properties were thoroughly examined. The prepared inks were printed using a laboratory-scale screen printing method, and the electrochemical performance of the printed electrodes was compared with those produced using traditional techniques. In the quest for efficient and lightweight rechargeable energy storage, new inks based on Si/rGO composites for printable Lithium-Ion Batteries (LIBs) have been investigated. By overcoming the conductivity and cycle stability issues of silicon, Yolk-shell Si/rGO structures have been synthesized to enhance LIB performance. These synthesized structures were utilized in the production of water-based anode inks. The inks were compared with the traditional CMC/SBR binder solution, using a CMC/PEO binder solution as the conventional production method. The CMC/PEO binder solution demonstrated superior rheological properties compared to the CMC/SBR solution. Inks containing 2.25 mL of DMPU per 1 g of electrode mass exhibited suitable viscosity for screen printing. Electrodes processed with the Si/rGO/CMC ink exhibited a capacity of 349 mAh g-1 after 45 cycles. This new ink facilitates the development of high-efficiency printed batteries. Finally, this research also has significant implications in terms of education. The findings discovered in this study and the methodologies developed could be incorporated into academic curricula and training programs for future scientists and engineers. Educational institutions have the opportunity to train students with the latest and most sustainable technologies. This could enable the next generation of researchers to contribute to the advancement of the energy storage industry. This knowledge transfer aims to maintain the momentum of innovation, ensuring that future progress prioritizes efficiency, sustainability, and safety
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by/4.0/
