Interphases in Solid-State Batteries: Mechanisms, Challenges, and Design Strategies

Dear Colleagues,

Solid-state batteries (SSBs) hold immense promise for revolutionizing energy storage by offering potentially higher energy densities, improved safety, and wider operating temperature ranges compared to conventional liquid electrolyte-based systems. However, the performance, longevity, and reliability of SSBs are critically governed by the complex physicochemical and electrochemical phenomena occurring at their internal interfaces and the resulting interphases—regions formed between electrodes and solid electrolytes, or between solid electrolyte grains. Understanding the formation mechanisms, characterizing the properties, addressing the inherent challenges, and developing effective design strategies for these interphases are paramount to unlocking the full potential of solid-state battery technology.

This Special Issue aims to bring together cutting-edge original research and comprehensive reviews that address these critical aspects. We seek to provide a platform for disseminating the latest advancements in elucidating the fundamental science of interphases in various SSB chemistries and exploring innovative approaches for their engineering and control.

Topics of Interest: 

This Special Issue invites submissions of original research articles and insightful review articles covering areas including, but not limited to, the following:

I.  Formation Mechanisms and Evolution of Interphases:

• Thermodynamic and kinetic studies of interphase formation at anode/solid electrolyte and cathode/solid electrolyte interfaces.
• Chemical and electrochemical reactions leading to the formation of Solid Electrolyte Interphases (SEIs) and Cathode Electrolyte Interphases (CEIs).
• Influence of processing conditions, contaminants, cycling parameters, and temperature on interphase composition, structure, and stability over time.
• Understanding the role of space-charge layers and their impact on ion transport near interfaces.

II. Advanced Characterization of Interphases:

• Application of advanced in situ and operando techniques (e.g., XPS, Auger, TEM/STEM-EELS, solid-state NMR, ToF-SIMS, synchrotron X-ray/neutron techniques, AFM-based methods) for probing the chemical, structural, morphological, and mechanical properties of interphases.
• Techniques for characterizing buried interfaces and dynamic interfacial processes during battery operation.
• Correlative microscopy and spectroscopy approaches for comprehensive interphase analysis.

III. Interfacial Challenges and Their Impact on SSB Performance:

• High interfacial impedance and its origins (e.g., poor contact, resistive interlayers, space-charge effects).
• Lithium dendrite nucleation and propagation mechanisms at/through interphases and solid electrolytes.
• Chemo-mechanical degradation at interfaces: stress generation, volume changes, cracking, delamination, and loss of contact.
• Electrochemical and chemical stability/reactivity of interphases with various electrode materials (e.g., Li metal, Si, S, high-voltage cathodes) and solid electrolytes (sulfides, oxides, polymers, composites).
• Impact of interphases at grain boundaries within polycrystalline solid electrolytes.

 IV. Design Strategies for Engineering Stable and Functional Interphases:

• Development of artificial SEI/CEI layers, protective coatings, and buffer interlayers to enhance stability and ion transport.
• Electrode surface modifications and electrolyte additives to promote favorable interphase formation.
• Novel solid electrolyte materials and compositions designed for improved interfacial compatibility and reduced reactivity.
• Strategies to enhance wetting and maintain intimate contact at solid–solid interfaces.
• Engineering approaches to manage chemo-mechanical stresses and improve the mechanical integrity of interphases.

V.  Modeling and Simulation of Interphases:

• First-principle (DFT) calculations of interfacial structures, reaction pathways, energetics, and electronic properties.
• Molecular dynamics (classical, ab initio, machine learning potentials) simulations of ion diffusion, structural evolution, and mechanical behavior at interphases.
• Continuum and multi-scale modeling approaches to predict chemo-mechanical coupling and degradation phenomena.
• Application of AI and machine learning for predicting interfacial stability, identifying descriptors for good interphases, and accelerating the design of interfacial materials.

Prof. Dr. Cengiz S. Ozkan
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Batteries is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• solid-state batteries
• interphases
• interfaces
• solid electrolyte interphase (SEI)
• cathode electrolyte interphase (CEI)
• solid electrolytes (sulfide, oxide, polymer)
• lithium metal anode
• all-solid-state batteries
• interfacial resistance
• dendrite suppression
• chemo-mechanics
• protective coatings
• in situ/operando characterization
• DFT modeling
• molecular dynamics
• machine learning in batteries