New method could improve future batteries
In his doctoral research, PhD student Rohan Patil has identified a new method for producing silicon nanoparticles for silicon-graphite battery anodes. The findings, which could contribute to higher-capacity lithium-ion batteries, will be presented at his thesis defence on 12 June.
The challenge is that silicon expands considerably during charging and discharging. Over time, this can cause the material to crack and degrade, reducing battery performance and lifespan.
In his doctoral research at Mid Sweden University, Rohan Patil has investigated a way to address this problem by transforming silicon into nanoparticles and combining them with graphite. The result is a composite anode material designed to combine silicon's high lithium-storage capacity with the stability and established performance of graphite.
"Silicon is abundant, environmentally friendly and already widely used in industry. If we can control its structure at the nanoscale, it becomes a very attractive material for future battery technologies," says Rohan Patil.
Unexpected phenomenon
The research began with efforts to create a porous silicon-graphite structure that could accommodate silicon's expansion during battery operation. During experiments, the researchers observed an unexpected phenomenon: the silicon broke down into nanoparticles.
After extensive studies, Patil and his colleagues found that hydrogen plays a crucial role in the process. Their experiments showed that silicon nanoparticles only formed under specific conditions and that hydrogen was necessary for the reaction to occur.
Understanding this mechanism became one of the central challenges of the project.
"We knew that the process worked, but understanding exactly how the nanoparticles formed was much more difficult. Identifying the required conditions and the role of hydrogen was a major part of the research," says Rohan Patil.
The researchers also observed changes on the silicon surface when hydrogen was present, providing important clues to the nanoparticle formation process.
Further studies on how to increase volumes
A key objective of Rohan Patil's research has been to develop a method that could eventually be integrated into industrial manufacturing processes. The team has identified the parameters required to produce the nanoparticles, but further work is needed to increase production volumes and gain greater control over particle size and distribution.
"We now know that silicon powder and hydrogen are essential components of the process. The next step is to study the reaction as it happens so that we can optimise it for different applications," says Rohan Patil.
Although the work focuses on lithium-ion battery anodes, the findings could have applications beyond energy storage, including solar energy and other technologies that rely on advanced silicon materials.
Welcome to the public defence
On 12 June 2026, Rohan Patil will defend his doctoral thesis, A Two-Pot Furnace Approach to Silicon Nanoparticle-Graphite Composite Anodes in Lithium-Ion Batteries, at Mid Sweden University. The defence will take place at 09:00 in room O102 at Campus Sundsvall and will also be available online via Zoom.