How Human Cartilage is Inspiring the Next Generation of Batteries
We all know the frustration of a degrading smartphone battery, but the physical reason behind it is a microscopic battle.
As global demand for high-energy lithium-ion batteries in electric vehicles and electronics surges, engineers are turning to nickel-rich cathodes. Yet these high-capacity materials suffer a fatal flaw: the constant swelling and shrinking during charging-discharging create immense internal stress. Over time, this dynamic pressure causes the battery particles to crack and fail, severely limiting their lifespan.
To unlock the next generation of high-performance batteries, scientists needed a way to cushion this microscopic violence.
Inspired by the stress-buffering properties of human cartilage, a research team led by Prof. CHEN Guohua, Chair Professor of the Department of Chemical and Biological Engineering (CBE) at HKUST, has developed an innovative solution.
Their study introduces an ultra-thin, shape-memory polymer nanocoating that acts as a shock absorber for battery particles. Using a unique chemical vapor deposition (CVD) technique, the team has engineered a resilient polymer that penetrates deep into the cathode material's microscopic grain boundaries.
Like the cartilage that protects our joints, this coating dynamically dissipates internal stress, suppressing intergranular cracking at the source. In the human body, cartilage can deform and dissipate external stress, protecting brittle bones from damage.
Replicating this at the nanoscale, the HKUST researchers have designed a crosslinked shape-memory polymer coating. The vapor penetrates deeply into the electrode secondary particles, coating the vulnerable internal boundaries between primary particles and polymerizing in situ.
This forms a resilient, stress-absorbing layer similar to cartilage in human joints, maintaining dynamic stability during prolonged battery cycling.
“The idea of applying CVD polymer coatings for energy storage materials was initiated during my sabbatical at MIT in 2005, where CVD polymers were successfully applied to pharmaceutical particles for controlled drug release,” said Prof. Chen, adding that his team was proud to be the first to successfully apply this technology to lithium-ion battery materials.
The innovation allows batteries to retain exceptional capacity after thousands of cycles and paves the way for industrial-scale deployment. With plans to scale production to 1,000 kilograms for commercial EVs and eVTOL aircraft, this biomimetic breakthrough proves that sometimes, the best way to advance cutting-edge energy technology is to learn from nature.
This research team comprises Prof. Chen, Dr. LIU Qiang, an HKUST PhD graduate and Research Assistant Professor in CBE, and Dr. LIU Yutong, a Postdoctoral Fellow in CBE.
The study was published in Nature Nanotechnology under the title “Dynamic delocalization of stress in brittle battery positive electrode active materials by shape-memory polymer nanocoating.”
You can read more about the research here.
