Development of iron-rich anode materials for lithium-ion battery technology from local FeCr alloys

Abstract

Energy is an indispensable concept for all creatures to survive. Energy is also needed to increase the quality of lives. At this point, it can be said that secondary batteries become important because they play a critical role in the widespread use of portable devices that are employed in defence, home appliance and medical applications. Among the secondary batteries, lithium-ion batteries stand out in terms of their light in weight, high safety, theoretical capacity and energy density. However, their high costs restrict their extensive uses. History shows that after the industrial revolution steam machines replaced manpower and fossil fuels that were used to prefer as the energy source of the machines. However, mankind was greedy. Countries that became stronger with the acceleration of industrialization sought new resources in different geographies to meet their ever-increasing energy needs. This quest has led to various energy crises until this date. The positive opportunities provided by the use of energy obtained from renewable energy sources rather than the use of limited energy resources such as fossil have been expressed in many different platforms. The discontinuity of such renewable energy in question is overcome by the development of energy storage technologies. Following the works of Galvani and Volta in the 18th century, the first battery types were produced by Exxon in the 1970s where titanium disulphide and lithium metal were used as the cathode and the anode materials, respectively. Then in the 1990s, Goodenough et al. created a great milestone for studies on energy storage technologies with the secondary battery system that they proposed. In this battery (LIB) design transition metals were used as cathode and carbon was used as the anode materials. The fact that in 2019, they were awarded the Nobel Prize thanks to their LIB design, officially documented the importance of such technology in the world history. Then in 1980, Armand published the intercalation mechanism of lithium metal in LIB. In 1991, Sony announced the introduction of the LIB as a product into the market. Today, the market of lithium-ion batteries is growing day by day, while the researches to improve their energy and power densities as well as safety are also increasing exponentially. Simply, a lithium ion battery consists of four main elements: separator, negative electrode (Anode) , positive electrode (Cathode) and electrolyte. In charging, lithium ions of the cathode pass through the electrolyte and get in to the negative electrode, while electrons follow the ions and move on the external circuit to go to the anode. Then in discharging, lithium ions leave the anode material and return to their initial place in the cathode material. Meanwhile, electrons direct the stored energy to the desired application. Examples of positive electrodes include LiCoO2, LiFePO4 and LiMnO2, and the most widely used negative electrodes are silicon, transition metal oxide, and graphite. These electrode materials are produced by a wide variety of synthetic methods. However, in many of these production methods, since the starting material is of high purity, industrial scaled production processes often require working with a continuous maintenance of high quality raw materials. In this type of production process, where raw materials are dependent on foreign countries, the input value becomes unstable which causes financial difficulties in the production for long term business.