The development of next-generation electrochemical energy storage technologies critically depends on our ability to observe and understand dynamic processes at buried electrode interfaces under realistic operating conditions. Ion transport, interphase evolution, degradation pathways, and mechanically induced failure mechanisms all manifest across multiple length and time scales. Operando soft-to-tender X-ray spectroscopy is uniquely suited to probe these processes with element-specific sensitivity. Yet, to fully harness these capabilities, the field must advance from isolated experiments toward integrated, automated, and data-centric research infrastructures.

As part of the BESSY II+ upgrade, Helmholtz-Zentrum Berlin (HZB) is currently designing and constructing the SoTeXS instrument, a new soft-to-tender X-ray spectroscopy beamline that will enter commissioning at the beginning of 2029. SoTeXS is being built entirely from scratch—featuring a new insertion device, novel monochromator architecture, optimized X-ray optics, and a fully redesigned experimental endstation. This contribution, therefore, presents not results from an existing instrument, but the conceptual framework and technical architecture underpinning SoTeXS and its role in shaping next-generation operando X-ray science.

A defining characteristic of SoTeXS is its highly automated sample environment, which enables reproducible, interface-sensitive measurements at two independent beamspots within the same experimental chamber. The automation concept integrates seamlessly with a robotics-based sample-logistics infrastructure. This concept enables short-, medium-, and long-duration operando experiments without continuous user presence. This approach not only increases reproducibility and throughput but also paves the way for remote industrial use cases where standardized operando analytics are essential.

The development of SoTeXS is tightly coupled to HZB’s broader digitalization strategy, which is currently being expanded across the entire photon-science domain. A FAIR-by-design data workflow ensures that all aspects of an experiment—from cell assembly and configuration to beamline setup, environmental conditions, and primary analysis results—are automatically captured as structured, machine-actionable metadata. These data are ingested into a scalable platform that supports provenance tracking, versioning, and interoperable re-analysis.

Crucially, the SoTeXS concept is further strengthened by the InViMOD [1] project, funded through the OSCARS (Open Science) framework. InViMOD develops advanced visualization, metadata standards, and digital workflows specifically tailored to operando experiments. It provides novel interactive data interfaces and FAIR-data pipelines that directly support SoTeXS’ scientific mission. Through InViMOD, visualization tools for complex operando datasets—spanning spectral, imaging, and electrochemical dimensions—will allow users to explore battery data intuitively and reproducibly. The combination of automated beamline operation and rich, standardized data structures uniquely positions SoTeXS to leverage AI and machine learning for pattern recognition, anomaly detection, and automated scientific insight.

Collectively, these developments mark a significant leap forward in how operando X-ray experiments are conceived and executed. Even before commissioning, SoTeXS already serves as a blueprint for how next-generation beamlines can integrate automation, digitalization, FAIR data principles, and AI-ready workflows to dramatically accelerate materials discovery. By coupling advanced photon science with autonomous experiment design and transparent data ecosystems, HZB is establishing a framework that will redefine operando studies of battery materials and other complex energy systems.

[1] https://oscars-project.eu/projects/invimod-intelligent-visualisation-multimodal-operando-data-energy-systems-fair-workflow