Using Bioinspiration to Optimise Battery Electrodes Architecture for High Rate Capability
Authors: Bouville Florian , Billaud Juliette Marie , Magrini Tommaso , Villevieille Claire , Studart André 
Published: February 2020

Natural materials, with the prime example of bone and seashells, can combine antagonist properties and thus result in plurifunctionality. For instance, bone needs to be porous to facilitate fast transport of body fluids and enable energy-effective locomotion, but at the same time be a strong and tough structural material. Understanding the principles of the relationship between microstructure and properties in those examples has led to new conceptual designs for materials exhibiting superior properties that would not be achievable with today’s homogeneous materials.

Energy devices such as batteries face precisely the same type of mutually exclusive constraints: maximizing the cell power density, thus using a large amount of material, while preserving an easy diffusion path for the charge carrier to enable high charging rate. The prevalent strategy to address this challenge has so far been to tune the chemistry of the electrode material. However, different approaches based on the fabrication of architectured electrodes have recently been proposed to tackle this problem. Minimising the ion and electron path tortuosity within thick architectured electrodes1–3 would lead to batteries capable of sustaining higher cycling rates and power densities.

We recently introduced a processing platform that offers radically new compositional, texture and shape control, enabling the fabrication of heterogeneous bio-inspired composites with unprecedented properties4,5. The necessary tools to characterize the resulting intricate porous microstructure include tomography (by X-Ray or FIB-SEM) and Finite Element Modelling to predict their diffusion properties.

In this presentation we will introduce the different porous structures that can be obtained through our bioinspired approaches at each different length scales. We will then use the imaging and modelling tools at our disposal to predict which scale is the most relevant for the optimization of antagonistic properties. Finally, a common electrode material with designed architecture will be discussed to show that our bio-inspired strategy is a promising route for the development of batteries with enhanced rate capability.

References

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3. Lai, W. et al. Ultrahigh-energy-density microbatteries enabled by new electrode architecture and micropackaging design. Adv. Mater.
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5. Le Ferrand, H., Bouville, F., Niebel, T. P. & Studart, A. R. Magnetically assisted slip casting of bioinspired heterogeneous composites. Nat. Mater.
14, 1172–1179 (2015).