Metal Sulfides as Potential Materials for Next Generation Lithium Ion Batteries: A Review

Lithium-ion batteries (LIBs) are indispensable in modern electronic instruments and electric vehicles because of their high energy density and long cycle life. However, the performance of traditional LIBs is constrained by limited theoretical specific capacities and structural stabilities, failing to meet the demands of next-generation high-performance applications. Transition metal sulfides are emerging as promising electrode materials due to their low cost, high theoretical capacities, and superior intrinsic properties. Compared to oxides, metal sulfides exhibit enhanced electrical conductivity, faster ion diffusion, and multi-electron transfer capabilities, which collectively enable higher energy density, better rate performance, and improved cycling stability. Flame spray pyrolysis (FSP) offers a scalable, cost-effective method for synthesizing functional structured electrode materials. This one-step process facilitates precise control over particle composition, and morphology, enabling complex modifications such as doping, homogeneous mixing, coating, and noble metal promotion/functionalization. FSP also produces metastable nanoparticle phases and allows direct deposition of materials onto electrodes without binders or solvents, streamlining electrode fabrication. The integration of FSP synthesis with electrode production in a continuous process chain holds immense potential for large-scale manufacturing of LIB electrodes. This approach is anticipated to revolutionize energy storage technologies, addressing the challenges of cost, performance, and scalability.