The ever-growing demand for high-performance batteries across various industries underscores the importance of advancing electrochemical energy storage systems. Research and development efforts in materials science are increasingly focused on enhancing the capabilities of batteries, particularly for applications like electromobility. Factors such as charging capacities, speeds, lifespan, safety, raw material availability, and CO2 balance are all crucial considerations in this pursuit.
A collaborative effort led by chemists Dr. Hanyu Huo and Prof. Dr. Jürgen Janek from Justus Liebig University Giessen, physicist Prof. Dr. Kerstin Volz from the University of Marburg, materials scientist Dierk Raabe from the Max Planck Institute for Iron Research in Düsseldorf, and theoretical material scientist Prof. Dr. Chandra Veer Singh from the University of Toronto, Canada, along with their teams, has delved into the properties of silicon anodes in solid-state batteries.
Their research suggests that silicon anodes hold significant potential for enhancing battery performance. Their findings on the stability, chemomechanics, and aging behavior of silicon electrodes have been published in the esteemed journal Nature Materials.
The research team employed a combination of experimental and theoretical methods to quantitatively assess the transport of lithium within the electrode, the substantial mechanical volume changes of silicon during charging and discharging, and its interaction with the solid electrolyte.
“This comprehensive and fundamental analysis marks a significant stride toward the potential utilization of silicon as an electrode material in solid-state batteries, a focal point of intensive international research,” notes Prof. Janek, a key contributor to the study.
Solid-state batteries represent an advanced iteration of lithium-ion batteries, aiming to replace the liquid organic electrolyte with a solid counterpart for enhanced storage properties, longevity, and safety. The pursuit of solid-state batteries has been a primary focus of global research for approximately a decade, with Prof. Janek's team at Giessen standing out as a leading academic group in this domain.
During the battery charging process, lithium is absorbed into the negative electrode, or anode. Prof. Janek elaborates, “This leads to significant mechanical challenges in a solid-state battery, as the silicon at the anode expands by several hundred percent.”
Moreover, the preferred solid electrolytes react with the stored lithium, resulting in capacity losses. Prof. Janek emphasizes, “Our recently published work provides a detailed quantitative evaluation of these aspects for the first time.”
While lithium metal is an ideal candidate for the anode due to its high storage capacity, the risk of internal short circuits under operating conditions necessitates exploring alternatives like silicon.
“Our findings underscore the considerable potential of silicon anodes for solid-state batteries, which can be further leveraged by optimizing battery interfaces,” Prof. Janek concludes.
Addressing the chemical and chemomechanical aging of silicon anodes requires additional material concepts. The research team has already demonstrated the efficacy of a polymer interlayer as part of this solution, highlighting avenues for further innovation and improvement in battery technology.
Source: University of Giessen