Design and Performance Evaluation of an Electrode based on Spinel Silicate and Lignin Composite as Cathode in Lithium-ion Battery

Sustainable energy is nowadays one of the most critical goals for any country, and achieving it can significantly impact the economy, politics, society, and the environment. Therefore, as one of the candidates for sustainable energy, batteries have allocated considerable importance to themselves. Among these, lithium-ion batteries have garnered attention as one of the most potent energy storage sources due to their excellent performance, good cycling life, and high reversible capacity. They are being considered for next-generation energy storage systems and are expected to become a vital component of future sustainable energy resources[۱]. It is anticipated that they will play a prominent role in the automotive and transportation sectors and more. Batteries consist of various components, and the study of cathodes as one of the critical battery components, where the oxidation reaction occurs, generating electric current, holds significant importance. Today, cathodes such as LiCoO_۲، LiNiO_۲، LiMn_۲ O_۴ and LiFePO_۴ are being used. Challenges such as maintaining capacity during charge-discharge processes, the use of expensive and limited materials like cobalt and nickel, cathode capacity reduction, and consequently, chemical changes in the cathode structure leading to the formation of a layer called CEI (cathode-electrolyte interphase), have caused these cathodes to be less effective in meeting energy demands. This has led to the study of other cathode materials with higher capacities[۲]. Recently, cathodes based on silicate-spinel like Li_۲ MSiO_۴ (M: Fe, Mn,…) have gained attention due to their high specific capacity and higher thermal decomposition temperature compared to other available cathode materials. Additionally, economically feasible silicon materials have been considered. However, these types of cathodes suffer from very low electronic conductivity and poor lithium diffusion. This research aims to investigate silicate spinel-based cathode materials concerning their structural stability and electrochemical performance. Modifications will be made to improve the properties of these compounds in terms of conductivity and permeability by altering their morphology and combining them with a carbon source such as lignin[۳]. One of the most important effects of lignin composite with LFS cathode material is the increase in power and cyclability as well as high coulombic efficiency in lithium-ion batteries