Solid-State Battery Technologies and Electrochemical Interfaces

Solid-state batteries represent a transformative advance in energy storage by replacing flammable liquid electrolytes with ion-conducting solids, thereby enhancing safety and potentially enabling higher energy densities. Key classes of solid electrolytes include ceramic oxides, sulphides and emerging halide materials, each offering distinctive trade-offs in ionic conductivity, electrochemical stability and mechanical properties. Efficient lithium-ion transport within the bulk electrolyte and across electrode|electrolyte interfaces is crucial to achieving rapid charge and discharge. However, intimate contact between rigid solids often degrades over cycling due to volume changes in active materials, chemical reactions at interfaces and the formation of resistive layers. Addressing these interfacial challenges has driven innovation in surface coatings, composite cathode design and tailored electrolyte chemistries. By combining advanced characterisation methods—from in situ electron microscopy to operando diffraction—with materials engineering, recent work has elucidated the fundamental origins of interfacial impedance and guided the development of stabilisation strategies. The global importance of these technologies spans electric vehicles, grid storage and portable electronics, where long cycle life, high power density and enhanced safety are paramount.

Research from Nature Portfolio

Recent studies have directly visualised the accumulation of ionic charge at the interface between high-voltage oxide cathodes and argyrodite electrolytes, revealing how space-charge layers hinder lithium transport and how built-in electric fields can be engineered to suppress their formation. Mechanistic investigations of interfaces between lithium germanium phosphide electrolytes and nickel-rich layered oxides have demonstrated that electronic transport limits the growth of interphase layers and that degradation accelerates at high states of charge through distinct oxidation pathways. A very recent advance has introduced a gradient oxy-thiophosphate coating on Ni-rich layered oxide particles, which conformally passivates the surface, prevents structural collapse and suppresses side reactions against sulphide electrolytes, yielding markedly improved cycle stability.

Research from all publishers

Composite cathode architectures incorporating single-crystal NMC811 paired with a halide solid electrolyte have achieved high discharge capacities and exceptional cycle life by combining high oxidative stability with minimised intergranular cracking, underscoring the importance of electrode microstructure. A wet-coating strategy using sub-5 nm ZrO₂ nanoparticles has been employed to form uniform protective layers on Ni-rich oxide cathodes, effectively suppressing interfacial side reactions and gas evolution, and enhancing rate capability in pelletised cells. Investigations into thiophosphate-based solid electrolytes with low Young’s modulus have shown that glassy electrolyte compositions can synergistically balance electrochemical and mechanical effects, accommodating volumetric changes of layered cathodes and maintaining intimate interfacial contact over extended cycling.

Solid-State Battery Technologies and Electrochemical Interfaces publication trend

The graph below shows the total number of articles in solid-state battery technologies and electrochemical interfaces across all publications each year (not limited to Nature Index journals).

Technical terms

All-solid-state battery: An electrochemical cell in which both electrolyte and electrodes are solids, eliminating liquid components.

Solid electrolyte: A non-liquid ionic conductor that facilitates ion transport between electrodes while providing mechanical separation.

Space-charge layer: A region at an electrode|electrolyte interface where ionic and electronic charge distributions differ from the bulk, creating a resistive barrier.

Composite cathode: A cathode structure combining active material, solid electrolyte and conductive additives to ensure both ionic and electronic pathways.

Gradient coating: A conformal surface layer with compositional variation designed to mitigate interfacial reactions and mechanical mismatch.

Interfacial impedance: The resistance to ion flow at the boundary between two solid phases, often dominated by reaction products or poor contact.

References

1. In-situ visualization of the space-charge-layer effect on interfacial lithium-ion transport in all-solid-state batteries. Nature Communications (2020).
2. A mechanistic investigation of the Li10GeP2S12|LiNi1-x-yCoxMnyO2 interface stability in all-solid-state lithium batteries. Nature Communications (2021).
3. A gradient oxy-thiophosphate-coated Ni-rich layered oxide cathode for stable all-solid-state Li-ion batteries. Nature Communications (2023).
4. High Energy Density Single-Crystal NMC/Li6PS5Cl Cathodes for All-Solid-State Lithium-Metal Batteries. ACS Applied Materials & Interfaces (2021).
5. Advanced Nanoparticle Coatings for Stabilizing Layered Ni‐Rich Oxide Cathodes in Solid‐State Batteries. Advanced Functional Materials (2022).
6. The interplay between (electro)chemical and (chemo)mechanical effects in the cycling performance of thiophosphate-based solid-state batteries. Materials Futures (2022).