Portable electronic devices, electric vehicles and stationary energy storage applications, which encourage carbon-neutral energy alternatives, are driving demand for batteries that have concurrently higher energy densities, faster charging rates, safer operation and lower prices. These demands can no longer be met by incrementally improving existing technologies but require the discovery of new materials with exceptional properties. Experimental materials discovery is both expensive and time consuming: before the efficacy of a new battery material can be assessed, its synthesis and stability must be well-understood. Computational materials modelling can expedite this process by predicting novel materials, both in stand-alone theoretical calculations and in tandem with experiments. In this review, we describe a materials discovery framework based on density functional theory (DFT) to predict the properties of electrode and solid-electrolyte materials and validate these predictions experimentally. First, we discuss crystal structure prediction using the ab initio random structure searching (AIRSS) method. Next, we describe how DFT results allow us to predict which phases form during electrode cycling, as well as the electrode voltage profile and maximum theoretical capacity. We go on to explain how DFT can be used to simulate experimentally measurable properties such as nuclear magnetic resonance (NMR) spectra and ionic conductivities. We illustrate the described workflow with multiple experimentally validated examples: materials for lithium-ion and sodium-ion anodes and lithium-ion solid electrolytes. These examples highlight the power of combining computation with experiment to advance battery materials research.

We review recent research into oxides of platinum group metals (pgms), in particular those of ruthenium and iridium, for use as electrocatalysts for the oxygen evolution reaction (OER). These are used in membrane electrode assemblies (MEAs) in devices such as electrolysers, for water splitting to generate hydrogen as fuel, and in fuel cells where they provide a buffer against carbon corrosion. In these situations, proton exchange membrane (PEM) layers are used, and highly acid-resilient electrocatalyst materials are required. The range of structure types investigated includes perovskites, pyrochlores and hexagonal perovskite-like phases, where the pgm is partnered by base metals in complex chemical compositions. The role of chemical synthesis in the discovery of new oxide compositions is emphasised, particularly to yield powders for processing into MEAs. Part I introduces the electrocatalytic splitting of water to oxygen and hydrogen and provides a survey of ruthenium and iridium oxide structures for oxygen evolution reaction catalysis.

We continue our review of recent research into oxides of platinum group metals (pgms), in particular those of ruthenium and iridium, for use as electrocatalysts for the oxygen evolution reaction (OER). In Part I (1), the electrocatalytic splitting of water to oxygen and hydrogen was introduced as a key process in developing future devices for various energy-related applications. A survey of ruthenium and iridium oxide structures for oxygen evolution reaction catalysis was presented. Part II discusses mechanistic details and acid stability of pgm oxides and presents the conclusions and outlook. We highlight emerging work that shows how leaching of the base metals from the multinary compositions occurs during operation to yield active pgm-oxide phases, and how attempts to correlate stability with crystal structure have been made. Implications of these discoveries for the balance of activity and stability needed for effective electrocatalysis in real devices are discussed.

“Nanomaterials for Lithium-Ion Batteries: Fundamentals and Applications” is edited by Rachid Yazami and is published by Pan Stanford Publishing Pte Ltd. The book covers the latest developments in new materials for lithium-ion batteries including examples of novel alloys, oxides and conversion materials for use as anodes and phosphates, high voltage spinels and layered oxides for use as cathodes. Composite structures incorporating reduced graphene oxide are considered along with thin films and nanowires. Emphasis is also placed on combining electrochemical test data with materials characterisation and detailed explanation of the mechanisms occurring.