Journal of Materials Chemistry A Editor's choice collection: Li-metal batteries

Abstract

This Editor's choice collection has been curated by Professor Serena A. Cussen, Scientific Editor of Journal of Materials Chemistry A, with a focus on advances in materials, metrologies and modelling for Li-metal batteries.

Solid-state Li-metal batteries are promising candidates for next-generation energy storage, offering high energy densities and the potential for enhanced safety. However, significant challenges remain, including optimising ionic conductivities, maintaining (electro)-chemical stability across a wide potential range, and addressing interfacial stability issues. While not an exhaustive compilation of all works published in Journal of Materials Chemistry A on Li-metal batteries, this collection highlights several recent advances in the field. These contributions focus on overcoming these challenges by exploring new material structures and architectures, understanding surface properties and the interfacial behaviour, and rationalising design of safer and longer-lasting batteries through advances in modelling and characterisation.

Three recent reviews in Journal of Materials Chemistry A exemplify some of these ongoing efforts. For instance, Wu and colleagues examine the applications of ionic liquid moieties as liquid- and polymer-based electrolytes for Li-metal batteries as well as their potential to stabilise interfaces (https://doi.org/10.1039/D4TA05906A). Zhuang and coworkers provide a comprehensive overview of developments in in situ and operando Raman spectroscopy as a tool to investigate electrode–electrolyte interfaces in Li-metal batteries, suggesting further advancements to enhance this technique (https://doi.org/10.1039/D3TA03514J). Meanwhile, Xu and colleagues address some of the outstanding challenges associated with the design of flexible anode-free Li-metal batteries (https://doi.org/10.1039/D4TA02003K).

Research papers in this collection consider new materials and architectures, including those more amenable to low Li-metal anode potentials. For example, Famprikis and coworkers consider the irreducible antifluorite Li_1+2xCl_1−xN_x phases, where experimental and computational approaches demonstrate the compositional flexibility afforded by this framework and provide insights into enhancing ionic conductivities (https://doi.org/10.1039/D4TA07521H). Alonso and colleagues examine the impact of cation disorder and defect structure on the transport properties of a new series of mixed-metal halide solid electrolytes (https://doi.org/10.1039/D3TA02781C). Pralong and coworkers investigate the effects of incorporating halogen elements into the Li–P–S–O solid electrolyte system, which show improved stability under ambient conditions compared with their undoped counterparts (https://doi.org/10.1039/D4TA04904G). Meanwhile, Sabato et al. demonstrate the use of stereolithography to fabricate complex 3D-printed LAGP solid electrolytes, achieving a reduction in total area specific resistance (https://doi.org/10.1039/D3TA01435E).

The collection also highlights recent advances in understanding interface behaviour. Abate and coworkers elegantly probe the interfaces of metallic anodes and coating materials to uncover the nuanced nature of materials interactions at these interfaces (https://doi.org/10.1039/D4TA00971A). Li and colleagues demonstrate that a synergistic effect of LiF and Li₃N at the solid electrolyte interface (SEI) promotes homogenous Li metal nucleation and growth (https://doi.org/10.1039/D3TA08019F). Pavone and coworkers employ density functional embedding theory to analyse the complex reactions of vinylene carbonate additives during cycling, which induce SEI formation at the Li-metal interface (https://doi.org/10.1039/D2TA08772C).

Insights from technique development and modelling are shaping design principles for Li-metal solid-state batteries. Siegel and coworkers apply multiscale modelling methods to explore how fast grain boundary diffusion within the Li anode may be exploited to minimise void formation, as an alternative to the application of high stack pressure (https://doi.org/10.1039/D3TA03814A). Canova and colleagues consider how adaptive polymer electrolytes can act as interlayers to maintain Li-metal/solid electrolyte interfacial contact and minimise void formation (https://doi.org/10.1039/D4TA08556F). Morey et al. report the development of operando Auger methods using an electron beam which permits mapping and visualisation of Li plating (https://doi.org/10.1039/D3TA00386H).

Further works are included in this Journal of Materials Chemistry A collection which demonstrate important advances in our understanding and design of Li-metal batteries.

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