<p>In this study, dual conducting phases were constructed in lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-doped poly(ethylene oxide)-<i>block</i>-poly(oligo(ethylene glycol) methyl ether methacrylate) (PEO-<i>b</i>-POEGMA) block copolymer (BCP) electrolytes. The distribution of lithium salt in the two phases was quantitatively analyzed using Fourier transform infrared (FTIR) spectrometry and the preferential location of lithium salt in the POEGMA-rich phase was observed. Small-angle X-ray scattering (SAXS) results indicated that PEO-<i>b</i>-POEGMA/LiTFSI formed microphase-separated but disordered structures in the range of salt doping ratio (<i>r</i>) from 0.027 to 0.220. At both low and high doping ratios (<i>r</i> = 0.027 and 0.220), the interphase thickness (<i>Δ</i>) and grain size (<i>L</i>) of the electrolytes were significantly temperature-dependent. In contrast, at intermediate doping ratios (<i>r</i> = 0.055 and 0.110), these morphological parameters remained largely invariant with temperature. Based on the quantified distribution of lithium salt in the two phases, we compared the experimental conductivity with the theoretical conductivity calculated under the situations where ion transport across the interphase was either allowed or restricted. It was revealed that elevated temperature and the formation of diffused interphase facilitated ion transport across the boundary.&#xa0;</p> Graphical Abstract <p></p>