➀ Traditional X-ray photoelectron spectroscopy (XPS) alters lithium battery anode protective layers during measurement, leading to inaccurate data;

➁ Stanford researchers developed cryo-XPS, freezing samples at −200°C to preserve the layer's natural state, revealing discrepancies in prior findings;

➂ This method provides accurate insights into battery interface chemistry, challenging past design assumptions and guiding future electrolyte development.