Neutron-Based Characterization of Lithium-Ion Battery Interfaces

Neutron-based characterisation employs the unique interaction between neutrons and light elements, such as lithium and hydrogen, to non-destructively probe the internal structure and chemistry of lithium-ion battery interfaces. Techniques including neutron reflectometry, neutron depth profiling and neutron tomography provide quantitative depth profiles, spatially resolved imaging and operando monitoring of key processes at electrode–electrolyte boundaries. These methods reveal the formation, composition and evolution of the solid electrolyte interphase (SEI) on anodes and the cathode–electrolyte interphase (CEI) on cathodes, both of which govern ion transport, cycle life and safety. By tracking lithium distribution, interphase growth and mechanical changes in real time, researchers gain insights into degradation mechanisms, dendrite formation and electrolyte wetting. Such information underpins the rational design of electrode coatings, novel electrolytes and cell architectures, with global significance for higher energy density, faster charging and improved durability in consumer electronics, electric vehicles and grid storage.

Research from Nature Portfolio

High-resolution four-dimensional correlative imaging has combined neutron and X-ray tomography with a virtual unrolling technique to map lithium diffusion and mechanical degradation in commercial primary and secondary cells. This approach directly visualises electrolyte penetration and lithium migration through spiral-wound electrodes, revealing subtle microstructural fluctuations that correlate with capacity fade. Operando neutron depth profiling has been used to quantify the spatial distribution of lithium during plating and stripping of lithium-metal anodes. By recording lithium density profiles as a function of current density, electrolyte composition and cycling history, this work uncovers reversible lithium uptake in current collectors and tracks the accumulation of inactive lithium over cycles, offering routes to mitigate dendrite formation and extend cycle life.

Neutron-Based Characterization of Lithium-Ion Battery Interfaces publication trend

The graph below shows the total number of articles in neutron-based characterization of lithium-ion battery interfaces across all publications each year (not limited to Nature Index journals).

Technical terms

Neutron reflectometry: A surface-sensitive scattering technique that measures the depth-dependent composition and structure of thin interphase layers by analysing reflected neutron intensity as a function of incident angle.

Neutron depth profiling (NDP): A method in which capture reactions of neutrons by lithium isotopes produce charged particles whose energy loss provides a depth profile of lithium concentration within electrodes.

Neutron tomography: Three-dimensional imaging by reconstructing neutron transmission data collected at different angles, yielding spatial maps of element distribution and morphology within intact cells.

Operando: Real-time measurement performed under actual operating conditions of a battery, enabling dynamic monitoring of interphase formation and ion transport.

Solid electrolyte interphase (SEI): A thin, passivating layer that forms on the anode surface during initial cycles, composed of inorganic and organic decomposition products, crucial for stabilising further cycling.

Cathode–electrolyte interphase (CEI): A protective layer that develops on cathode surfaces, modulating ion desolvation, suppressing parasitic reactions and influencing high-rate performance.

References

1. Fast Lithium Intercalation Mechanism on Surface‐Modified Cathodes for Lithium‐Ion Batteries. Advanced Energy Materials (2023).
2. Visualizing Lithium Ion Transport in Solid‐State Li–S Batteries Using 6Li Contrast Enhanced Neutron Imaging. Advanced Functional Materials (2023).
3. Operando monitoring the lithium spatial distribution of lithium metal anodes. Nature Communications (2018).
4. 4D imaging of lithium-batteries using correlative neutron and X-ray tomography with a virtual unrolling technique. Nature Communications (2020).
5. Operando neutron imaging study of a commercial Li-ion battery at variable charge-discharge current densities. Electrochimica Acta (2022).