Gu Research Group in Mechanical Engineering
Mechanical Behavior of Energy Materials
The Gu Group studies why materials break, and how to prevent this. Our focus is on materials for energy technologies, such as battery materials, materials for hydrogen infrastructure and magnetic materials for use in electric machines. To accomplish this, we develop tools that allow us to understand how deformation at the smallest, nano length scales influence behavior at practical length scales relevant to devices. This includes in-operando microscopy of materials under coupled mechanical and electrochemical fields, nano and macroscale additive manufacturing, and mechanical testing in extreme environments.
Recent News
Dendrite initiation and deflection in biaxially stressed solid electrolytes
Lithium-metal solid-state batteries offer advantages of high energy density and improved safety compared with lithium-ion batteries. However, solid-state batteries fail through short-circuiting even at low charging rates (less than 1 mA cm−2) due to lithium dendrite initiation and propagation.This work reconciles the surface and interior initiation mechanisms in garnet solid electrolytes and demonstrates that in-plane biaxial compressive stress can prevent both from short-circuiting the cell.
Published in Nature in July 2026!
Direct observation of strain-enhanced hydrogen segregation and failure at high-angle grain boundaries in nickel
Understanding the mechanisms underlying hydrogen embrittlement remains difficult, even in single-element metals. Both microstructure and stress state influence hydrogen distribution in metals and alloys, which impacts deformation and failure. In this work, a suite of novel in situ investigation techniques are employed to reveal the influence of strain on hydrogen segregation in nickel.
Published in Acta Materialia in July 2025!
Heterogeneous doping via nanoscale coating impacts the mechanics of Li intrusion in brittle solid electrolytes
Lithium dendrite intrusion in solid-state batteries limits fast charging and causes short-circuiting, yet the underlying regulating mechanisms are not well-understood. This study reveals a chemo-mechanical mechanism via surface heterogeneous Ag+ doping affecting lithium intrusion into a brittle solid electrolyte (LLZO), complementing present bulk design rules to minimize mechanical failures in solid-state batteries.
Published in Nature Materials in January 2026!
Open Positions
Prospective postdocs and graduate students who have already been accepted to Stanford University can contact us with a CV, and a request to set up a meeting to discuss research interests.
