Beyond　the　high　theoretical　capacity,　conversion-alloying　metal　chalcogenides　(CAMCs)　exhibit　exceptional　high-rate　performance　as　Li-ion　battery　electrodes.　However,　the　inherent　origin　of　the　high-rate　performance　remains　elusive,　especially　given　the　lower　intrinsic　conductivity　of　CAMCs.　Here,　the　correlation　between　phase　evolution　and　charge　transport　dynamics　in　fully　activated　CAMCs　is　systematically　investigated,　elucidating　a　current-adaptive　Li-ion　storage　mechanism　to　explain　the　anomalous　high-rate　performance.　Briefly,　the　deconversion　reaction　manipulated　by　ion　diffusion　acts　as　a　＇regulator＇　to　adaptively　modulate　the　transition　from　metal　(high　electronic　conductivity)　and　lithium　chalcogenides　(high　ionic　conductivity)　to　CAMCs,　thus　removing　the　charge　transport　bottleneck　without　affecting　the　formation　of　the　metal　feedstock　required　for　the　alloying　reaction.　On　this　basis,　the　high　capacity　can　be　maintained　at　high　rates　through　a　＇fading-free＇　alloying　reaction.　This　study　offers　a　novel　perspective　for　the　design　of　high-rate　electrode　materials.　©　2024　Wiley-VCH　GmbH.