(Electro)chemical stability of Si/LPSCl composite anodes. AHAADF-STEM image of Si particles and corresponding EDS map. bTEM image of a Si particle. vsHAADF-STEM image filtered by average background subtraction at the Si interface | LPSCl. dElectronic and ionic conductivities of just mixed Si/LPSCl as a function of time. e, Procedure for resting and impedance measurements based on a three-electrode cell. The inset shows the three-electrode cell configuration. FNyquist plot and corresponding equivalent circuit used to evaluate impedance data (working electrode versus RE). gNyquist plots of a typical cell with long-term rest. h, A.int as a function of the square root of time (t0.5). Credit: Natural materials (2024). DOI: 10.1038/s41563-023-01792-x
High-performance batteries are needed for a wide range of applications and demand is growing rapidly. Therefore, the research and development of electrochemical energy storage systems, especially for electromobility, constitutes one of the most important areas of work in materials science worldwide. The focus is not only on battery capacities and charging speeds, but also on service life, safety, availability of raw materials and CO.2 balance.
Chemists Dr. Hanyu Huo and Prof. Dr. Jürgen Janek (both Justus Liebig University Giessen), the physicist Prof. Dr. Kerstin Volz (University of Marburg), materials scientist Dierk Raabe (Max Planck Institute for Iron Research, Düsseldorf) and theoretical material scientist Prof. Chandra Veer Singh (University of Toronto, Canada) and his teams studied the properties of silicon anodes in solid-state batteries.
They came to the conclusion that these anodes have great potential to improve the performance of these batteries. Their findings on the stability, chemomechanics and aging behavior of silicon electrodes were published in the journal Natural materials.
For the investigations, the research team combined various experimental and theoretical methods to quantitatively evaluate the transport of lithium in the electrode, the strong mechanical volume change of silicon during the charging and discharging processes and the reaction with the solid electrolyte.
“This comprehensive and fundamental analysis represents an important step towards the possible use of silicon as an electrode material in solid-state batteries, which is currently the subject of intensive international research,” says Professor Janek, one of the authors of the study.
The solid-state battery is an advanced concept of the lithium-ion battery, which currently operates with a liquid organic electrolyte. The ultimate goal is to use a solid electrolyte, which promises even better storage properties, longer life and increased safety. The development of solid-state batteries has been the subject of intensive research worldwide for around 10 years, and the Giessen team led by Professor Janek is one of the leading academic groups in this field.
During the charging process of a battery, lithium is absorbed into the negative electrode, the anode. “This causes the silicon at the battery anode to expand by several hundred percent, leading to considerable mechanical problems in a solid-state battery,” explains Professor Janek.
“In addition, preferred solid electrolytes react with stored lithium, which also leads to capacity losses. Our recently published work evaluates these aspects quantitatively and in detail for the first time.”
When developing more powerful solid-state batteries that can compete with conventional lithium-ion batteries, the anode must be made of a material with particularly high storage capacity, ideally a lithium metal. However, this carries a risk of internal short circuiting under operating conditions, which is why silicon is being explored as an alternative with equally high storage capacity.
“Our results show that the silicon anode has considerable potential for use in solid-state batteries, which could be exploited by intelligently adapting the battery interfaces,” explains Professor Janek.
Additional material concepts are needed to overcome chemical and chemo-mechanical aging of silicon anodes. Part of this solution could be a polymer interlayer, as the German and Canadian research team has already been able to demonstrate.
More information:
Hanyu Huo et al, Chemomechanical failure mechanisms of silicon anode in solid-state batteries, Natural materials (2024). DOI: 10.1038/s41563-023-01792-x
Provided by the University of Giessen
Quote: How silicon can improve the performance of solid-state batteries (January 26, 2024) retrieved January 26, 2024 from
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