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Blended electrode materials containing high‐capacity silicon (Si) and robust graphite (Gr) materials are considered advanced alternatives to pure graphite electrodes used in Li‐ion batteries. Understanding the component‐specific lithiation and delithiation behavior and electrochemical interactions between the blended materials is of crucial importance for targeted optimization of composition and microstructural design, yet hardly addressed to date. Herein, a model‐like Si/Gr blended electrode and special electrochemical cell are introduced to directly capture the component specific behaviors for the first time. This includes studies of the formation cycles, the reaction distribution between Si and Gr, the component‐specific contributions to the capacity at different charge and discharge rates, and the internal dynamics during pulse loads and subsequent relaxation. The deconvolution of the components’ behavior during operation provides fundamental insights that contribute to a profound understanding and targeted optimization of Si/Gr blended electrodes. Furthermore, the application of the presented experimental approach can serve scientists to identify and study other advanced materials combinations as blended electrodes for rechargeable batteries.

Blending different types of active materials in one electrode is a great opportunity to improve the overall performance of lithium‐ion batteries. Despite considerable progress in the recent years, basic interactions, such as the specific impact of a single component on the blends’ properties, are not satisfactorily understood at the moment. In this study, the electric loads of the individual components of a blend are investigated using a special experimental setup in combination with model‐like blended electrodes. Systematic studies on the impact of type and mass fraction of the components are conducted for different nominal charge and discharge rates. The experiments reveal that the single components can be charged and discharged independent from each other, according to their characteristic redox activities and the overpotential during operation. This can lead to high effective electric loads (C‐rates) subjected to a single component despite a comparatively low total current applied to the electrode. Based on the experimental results, a simple model is developed to estimate maximum effective C‐rates of the individual components in an arbitrary blend system. These novel insights are discussed in regarding advantages and disadvantages of battery electrodes with multiple active materials.

The development of advanced battery materials requires fundamental research studies, particularly in terms of electrochemical performance. Most investigations on novel materials for Li‐ or Na‐ion batteries are carried out in 2‐electrode half‐cells (2‐EHC) using Li‐ or Na‐metal as the negative electrode. Although such cells are easy to assemble and generally provide sufficient stability, scientists should be aware of any effects that may influence the measurements, and care should be taken when interpreting the corresponding results. The present work addresses specific effects that can affect the electrochemical response of measurements in 2‐EHC. Critical points to be considered for long‐term cycling tests and impedance analyses are discussed and illustrated with relevant examples. The different behavior of electrochemically deposited and pristine alkali metal electrodes is shown, deriving the corresponding impact on the characterization of the actual material of interest. We demonstrate possible impacts of anode‐cathode crosstalk effects on the evaluation of measurements in 2‐EHC and highlight challenges and pitfalls in the interpretation of measurements in 2‐EHC with respect to kinetic and thermodynamic properties and battery performance. These findings contribute to the understanding of the limitations of electrochemical characterization in 2‐EHCs and should be carefully considered by researchers when evaluating novel battery materials.