Abstract <p>Polymer electrolytes are critical for high-energy-density solid-state batteries (SSBs), yet their X-ray photoelectron spectroscopy (XPS) characterization is plagued by irradiation-induced artifacts, particularly false LiF signals. Herein, we demonstrate that poly(ethylene oxide)-based electrolytes suffer from severe X-ray irradiation-induced decomposition, which is significantly accelerated by the electron flux from the conventional charge neutralization gun, leading to exacerbated Li salt breakdown and artifactual LiF formation. In contrast, poly(vinylidene fluoride)-based electrolytes, while more radiation-resistant, are prone to a different failure mode dominated by inadequate charge compensation, which also results in misleading Li⁺ migration and LiF signals. In addition, we introduce a simple yet optimized protocol, which replaces the neutralization gun with a microporous copper foil for charge compensation. This approach effectively suppresses the charge-compensation-induced decomposition pathway, thereby excluding the LiF artifacts and yielding highly reliable surface analysis. This facile method requires no equipment modification, offering a robust tool to decouple genuine interfacial reactions from experimental artifacts. By enabling artifact-free characterization, it lays the groundwork for dynamic evolution in polymer SSBs.</p> Highlights <p>This work reveals that the electron flux from the conventional charge neutralization gun, rather than X-ray irradiation alone, is the primary driver of artifactual LiF formation during XPS characterization of polymer solid electrolytes. An optimized protocol using microporous copper foil for charge compensation is introduced, effectively suppressing irradiation-induced artifacts without instrument modification or cryogenic conditions.</p> Discussion <p>The fundamental mechanisms of irradiation-induced decomposition in polymer electrolytes during XPS characterization, particularly the synergistic effect of X-rays and electron flux, remain insufficiently elucidated.</p> <p>The practical applicability of artifact-mitigation strategies for reliable XPS analysis under real battery operating conditions or during <i>in situ</i>/operando characterization is still largely unexplored.</p> <p>A systematic understanding of the intrinsic irradiation resistance across different polymer hosts and its correlation with material properties is currently lacking.</p> Graphical abstract <p></p>