Researchers from Skoltech, MSU, and the IDEA Research Center have developed a method to analyze the mechanical degradation of lithium-ion batteries during operation. The study, supported by a Russian Science Foundation grant, was published in the journal Measurement.
The team utilized a modified CR2032 coin cell with a specialized access window and a flat diamond indenter. This setup allowed for real-time monitoring of cathode material properties, specifically focusing on high-nickel NMC811 cathodes, while avoiding the inaccuracies of previous methods that required disassembling batteries.
Experiments revealed that as the cathode transitions into the high-voltage H3 phase, its ability to undergo plastic deformation drops by 28%. While hardness and elastic modulus remained stable, this loss of plasticity increases the risk of particle cracking and structural failure when operating above 4.2 volts.
The new experimental platform provides quantitative data for calibrating multi-scale computational models. These findings aim to assist engineers in predicting internal stress and crack propagation, ultimately supporting the design of more durable and safer high-energy-density batteries for electric vehicles and portable electronics.
