Revisiting the High‐Entropy Paradigm for Ni‐Rich Cathodes: Dopant‐Induced Surface Engineering as the Key to Stability

ABSTRACT High‐entropy doping is a promising strategy for stabilizing high‐Ni layered cathodes, yet the origin of performance enhancement—whether from configurational entropy or specific dopant chemistry—remains ambiguous. Here, we systematically deconvolute these competing effects in Co‐free, Ni‐rich cathodes. By comparing materials with identical entropy but different dopants (W–Nb–Mg vs Zr–Ti–Mg), we demonstrate that dopant chemistry is the dominant factor governing electrochemical performance. The W/Nb/Mg‐doped cathode exhibited vastly superior cycling stability, which is attributed to the formation of a thin, passivating rock‐salt surface phase that fosters a robust, LiF‐rich cathode‐electrolyte interphase. In contrast, increasing configurational entropy by adding more elements (W–Nb–Mg–Zr–Ti–Al) primarily enhanced bulk mechanical properties and suppressed detrimental phase transitions, but yielded only marginal gains in cycling stability over the lower‐entropy W/Nb/Mg‐doped counterpart. Our findings underscore that individual dopant chemistry remains paramount, even within high‐entropy strategies. We therefore challenge the prevailing paradigm of maximizing entropy, proposing instead that a chemically informed doping strategy focused on engineering stable surface phases is a more rational and effective pathway toward next‐generation lithium‐ion battery cathodes with exceptional durability.