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1. Computation‐Guided Design of LiTaSiO ₅ , a New Lithium Ionic Conductor with Sphene Structure

   https://doi.org/10.1002/aenm.201803821  

   Xiong, Shan; He, Xingfeng; Han, Aijie; Liu, Zhantao; Ren, Zhensong; McElhenny, Brian; Nolan, Adelaide_M; Chen, Shuo; Mo, Yifei; Chen, Hailong (April 2019, Advanced Energy Materials)

   Abstract The development of all‐solid‐state Li‐ion batteries requires solid electrolyte materials with many desired properties, such as ionic conductivity, chemical and electrochemical stability, and mechanical durability. Computation‐guided materials design techniques are advantageous in designing and identifying new solid electrolytes that can simultaneously meet these requirements. In this joint computational and experimental study, a new family of fast lithium ion conductors, namely, LiTaSiO₅with sphene structure, are successfully identified, synthesized, and demonstrated using a novel computational design strategy. First‐principles computation predicts that Zr‐doped LiTaSiO₅sphene materials have fast Li diffusion, good phase stability, and poor electronic conductivity, which are ideal for solid electrolytes. Experiments confirm that Zr‐doped LiTaSiO₅sphene structure indeed exhibits encouraging ionic conductivity. The lithium diffusion mechanisms in this material are also investigated, indicating the sphene materials are 3D conductors with facile 1D diffusion along the [101] direction and additional cross‐channel migration. This study demonstrates a novel design strategy of activating fast Li ionic diffusion in lithium sphenes, a new materials family of superionic conductors. 

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2. Manipulating the diffusion energy barrier at the lithium metal electrolyte interface for dendrite-free long-life batteries

   https://doi.org/10.1038/s41467-024-47521-z  

   Pokharel, Jyotshna; Cresce, Arthur; Pant, Bharat; Yang, Moon Young; Gurung, Ashim; He, Wei; Baniya, Abiral; Lamsal, Buddhi Sagar; Yang, Zhongjiu; Gent, Stephen; et al (April 2024, Nature Communications)

   Abstract Constructing an artificial solid electrolyte interphase (SEI) on lithium metal electrodes is a promising approach to address the rampant growth of dangerous lithium morphologies (dendritic and dead Li⁰) and low Coulombic efficiency that plague development of lithium metal batteries, but how Li⁺transport behavior in the SEI is coupled with mechanical properties remains unknown. We demonstrate here a facile and scalable solution-processed approach to form a Li₃N-rich SEI with a phase-pure crystalline structure that minimizes the diffusion energy barrier of Li⁺across the SEI. Compared with a polycrystalline Li₃N SEI obtained from conventional practice, the phase-pure/single crystalline Li₃N-rich SEI constitutes an interphase of high mechanical strength and low Li⁺diffusion barrier. We elucidate the correlation among Li⁺transference number, diffusion behavior, concentration gradient, and the stability of the lithium metal electrode by integrating phase field simulations with experiments. We demonstrate improved reversibility and charge/discharge cycling behaviors for both symmetric cells and full lithium-metal batteries constructed with this Li₃N-rich SEI. These studies may cast new insight into the design and engineering of an ideal artificial SEI for stable and high-performance lithium metal batteries. 

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3. Insights into Lithium Sulfide Glass Electrolyte Structures and Ionic Conductivity via Machine Learning Force Field Simulations

   https://doi.org/10.1021/acsami.4c00618  

   Zhou, Rui; Luo, Kun; Martin, Steve W; An, Qi (April 2024, ACS Applied Materials & Interfaces)

   Sulfide-based solid electrolytes (SEs) are emerging as compelling materials for all-solid-state batteries (ASSBs), primarily due to their high ionic conductivities and robust mechanical stability. In particular, glassy SEs (GSEs) comprising mixed Si and P glassformers show promise, thanks to their efficient synthesis process and their intrinsic ability to prevent lithium dendrite growth. However, to date the complexity of their glassy structures hinders a complete understanding of the relationships between their structures and properties. Here, new machine learning force field (ML- FF) specifically designed for lithium sulfide-based GSEs has been developed. This ML-FF has been used to investigate the structural characteristics, mechanical properties, and lithium ionic conductivities in binary lithium thiosilicate and lithium thiophosphate GSEs, as well as their ternary mixed glassformer (MGF) lithium thiosilicophosphate GSEs. Molecular dynamic (MD) simulations using the ML-FF were conducted to explore the glass structures in varying compositions, including binary Li2S-SiS2 and Li2S-P2S5, as well as ternary Li2S-SiS2-P2S5. The simulations with the ML-FF yielded consistent results in terms of density, elastic modulus, radial distribution functions, and neutron structure factors, compared to DFT and experimental work. A key focus of this study was to investigate the local environments of Si and P molecular clusters. We discovered that most Si atoms in the Li2S-SiS2 GSE are situated in an edge-sharing environment, while the Li2S-P2S5 glass contained a minor proportion of edge-sharing P2S62- environments. In the ternary 60Li2S-32SiS2-8P2S5 glass, the ML-FF predicted similar P environments as observed in the binary Li2S-P2S5 glass. Additionally, it indicated the coexistence of corner and edge-sharing between PS4 and SiS4 tetrahedra in this ternary composition. Concerning lithium ionic conductivity at 300K, all studied glass compositions exhibited similar magnitudes and followed the Arrhenius relationship. The 50Li2S-50SiS2 glass displayed the lowest conductivity at 2.1 mS/cm, while the 75Li2S-25P2S5 composition exhibited the highest at 3.6 2 mS/cm. The ternary glass showed a conductivity of 2.57 mS/cm, sitting between the two. Interestingly, the predicted conductivities were about an order of magnitude higher than experimental values for the binary glasses but aligning more closely with that of the ternary glass. Moreover, an in-depth analysis of lithium-ion diffusion over the MD trajectory in the ternary glass demonstrated a significant correlation between diffusion pathways and the rotational dynamics of nearby SiS4 or PS4 tetrahedra. The ML-FF developed in this study shows immense potential as a versatile tool for exploring a broad spectrum of solid-state and mixed-former sulfide-based electrolytes. 

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4. Impacts of vacancy-induced polarization and distortion on diffusion in solid electrolyte Li ₃ OCl

   https://doi.org/10.1098/rsta.2019.0459  

   Mehmedović, Zerina; Wei, Vanessa; Grieder, Andrew; Shea, Patrick; Wood, Brandon C.; Adelstein, Nicole (November 2021, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences)

   Lithium-rich oxychloride antiperovskites are promising solid electrolytes for enabling next-generation batteries. Here, we report a comprehensive study varying Li + concentrations in Li 3 OCl using ab initio molecular dynamics simulations. The simulations accurately capture the complex interactions between Li + vacancies ( V Li ′ ), the dominant mobile species in Li 3 OCl . The V Li ′ polarize and distort the host lattice, inducing additional non-vacancy-mediated diffusion mechanisms and correlated diffusion events that reduce the activation energy barrier at concentrations as low as 1.5% V Li ′ . Our analyses of discretized diffusion events in both space and time illustrate the critical interplay between correlated dynamics, polarization and local distortion in promoting ionic conductivity in Li 3 OCl . This article is part of the Theo Murphy meeting issue ‘Understanding fast-ion conduction in solid electrolytes’. 

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5. Calix[4]pyrrole‐Based Wavy Covalent Organic Framework: A Protective Layer for High Performance Lithium‐Metal Batteries

   https://doi.org/10.1002/smll.202506365  

   Tian, Jinya; Liao, Yaqi; Zhu, Yaling; Li, Yi; He, Yanlei; Zhou, Jianqiao; Yao, Yonggang; Yuan, Lixia; Sessler, Jonathan L; Huang, Yunhui; et al (September 2025, Small)

   Abstract Practical applications of lithium metal batteries are often limited by low cycling efficiencies and uncontrolled lithium dendrite growth caused by unstable and heterogeneous lithium‐electrolyte interfaces. To address this issue, a calix[4]pyrrole‐based wavy covalent organic framework (WCOF) is developed that acts as a protective layer to suppress Li dendrite growth and reduce side reactions on the Li anode. The presentWCOFis porous and contains calix[4]pyrrole units acting as “molecular traps” that allow efficient PF₆⁻anion capture while allowing for uniform Li⁺diffusion. This provides structurally stable artificial protective layers that permit high Li⁺transference numbers. The resulting solid electrolyte interphases permit ultralong‐term stable cycling at a current density of 1 mA cm⁻²and reversible lithium plating/stripping (over 2500 h) at an areal capacity of 2 mAh cm⁻². The protected anodes of this study also demonstrated excellent cell stability through 260 cycles when paired with high‐voltage cathodes (NCM811 with high mass loading: 20 mg cm⁻²). 

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