In this example, charge photometry is used to monitor particle degradation in a high-rate anode material across repeated fast charge-discharge cycles. The technique quantifies cracking and fragmentation in real time, helping researchers identify which morphological features impact durability – and how to optimise them for longer battery life.
In the example below, charge photometry quantifies the mechanical degradation of the high-rate anode material, Nb14W3O44 (NWO) over successive fast charge-discharge cycles.
Crack detection in active particles allows for quantification of both fragmented and intact particles within a fixed population over multiple charge-discharge cycles.
Initially, the number of cracked particles increases with each successive 5C cycle, gradually reaching a plateau after the fifth cycle. However, when the delithiation rate is increased to 20C, a sharp rise in cracked particles is observed, suggesting that faster delithiation significantly accelerates particle fragmentation.
In addition to crack detection, morphological parameters – such as particle length and width – can be extracted from the optical images. This enables the identification of correlations between specific particle morphologies and their susceptibility to degradation.
In this example, NWO particles of longer length (>3 µm) were more prone to cracking (there was no correlation between cracking and particle width). Such knowledge informs the optimisation of particle morphology to reduce the likelihood of particle degradation at faster charging rates.
Charge photometry offers a powerful solution for accelerating the optimisation of anode materials. By revealing how charging rates and formulation changes impact particle degradation, researchers can: