Research

In the critical area of sustainable energy storage, solid-state batteries (see Figure 1) have attracted considerable attention due to their potential safety, energy-density and cycle-life benefits. The main proposed benefit of solid-state batteries has been their increased safety, which stems from the absence of flammable liquid electrolytes typically employed in Li-ion cells. The central electrolyte-related challenges for practical solid-state devices include utilization of metal anodes, stabilization of interfaces and the maintenance of physical contact, the solutions to which hinge on gaining greater knowledge of the underlying properties of solid electrolyte materials.

Figure 1: Representation of a bipolar-stacked solid-state battery.^[1]

While significant attention is still devoted to intrinsic Li⁺ conductivity in solid electrolytes, many challenges remain for future solid-state applications. In the development of solid-state batteries, one the most pressing challenges are finding solid electrolytes that are electrochemically stable against electrodes, maintaining physical contact between components over many Li intercalation/extraction cycles and suppressing Li-dendrite formation.

Utilizing modeling, our research attempts to identify the root-cause of these problems, providing viable solutions.

Relevant references

1. T. Famprikis, P. Canepa et al., Nature Mat. (2019)
2. P. Canepa et al., Chem. Mater. 30, 9, 3019-3027 (2018)
3. P. Canepa, S.-H. Bo, G. S. Gautam, B. Key, W. D. Richards, T. Shi, Y. Tian, Y. Wang, J. Li, G. Ceder.; Nat. Commun. 8, 1759 (2017)
4. J. A. Dawson, P. Canepa, et al. J. Am. Chem. Soc. 140, 362–368 (2018)

Energy storage technologies are key for a clean energy economy but currently are in need of considerable advancements in energy density beyond the metrics of commercial Li-ion batteries. The rapidly expanding field of nonaqueous monovalent and multivalent intercalation batteries offers (see Figure 1) a promising way to overcome safety, cost, and energy density limitations of the current battery technology.

Figure 1: Number of publications from 1985 until 2015 featuring multivalent electrochemistry.^[1]

We actively work to advance the development of novel monovalent (Li and Na) multivalent ion (Mg, Zn and Ca) batteries by leveraging advanced computational materials science. We study the dynamic of multivalent-ion during stripping and deposition at the anode electrodes, the intercalation processes in high-voltage positive materials by unveiling complex features in their compositional phase diagrams. Our research also focuses on identified the bottlenecks of multivalent transport in these electrodes.

Relevant references

1. D. Aurbach, et al., Nature 407, 724–727 (2000)
2. P. Canepa, G. S. Gautam, et al., Chem. Rev. 117, 5, 4287-4341 (2017)
3. Z. Rong, et al., Chem. Mater. 27, 17, 6016-6021 (2015)

Light has been utilized as a communication device for many centuries. Recently, non-linear optics (NLO) and second harmonic generation (SHG) have been at the heart of several technological revolutions. With the advent of the internet, conveying information and data by means of fiber-optics and lasers have transformed telecommunications. The development of fiber-optic devices with increased performance has fueled a surge of interest in the development of materials with ever-increasing data-transfer capabilities.

Materials, such as LiNbO₃ and LiTaO₃ with NLO and SHG are at the core of high-speed electro-optic modulator devices, significantly boosting the transmission capacities of the telecommunication infra-structure (~10 Gbit s^-1).

Figure 1: Computed birefringence Δn and 2V angle of metal-free perovskite materials. More detail about this study can be found in Ref. [1]

The demand for apparatus with increased performance requires the development of novel inexpensive NLO materials and every year the electronic and telecommunication industries demands the production of $40.000 tons of LiNbO₃. The soaring costs of lithium and niobium, and thus requires the development of the new generation of NLO materials relying on more earth-abundant elements.

Through computational materials science we unravel the complex mechanisms that maximize the interaction of light with advanced NLO materials. We use high-throughput techniques to discover novel NLO materials, as well as to unveil the structure properties relationship in novel SHG and NLO materials.

Relevant references

1. P. A. Franken, A. E. Hill, C. W. Peters and G. Weinreich, Phys. Rev. Lett., 7, 118–119 (1971)
2. T. W. Kasel, Z. Deng, A. M. Mroz, C. H. Hendon, K. T. Butler and P. Canepa, Chem. Sci., 10, 8187-8194 (2019)
3. P. S. Halasyamani and K. R. Poeppelmeier, Chem. Mater. 10, 2753-2769 (1998).
4. P. S. Halasyamani and J. M. Rondinelli, Nat. Commun., 9, 2972 (2018)