fig4

Figure 4. Overview of BIEF-enhanced ion transmission in LIBs, Na-ion batteries and CFCs. (A) Illustration of facilitation of Li⁺ charge transport under a BIEF during discharge (left) and charge (right). Copyright from Ref.^[13]. (B) Li-ion transport mechanism at heterogeneous LiCoO₂ cathode/β-Li₃PS₄ solid electrolyte interface in a LIB. Copyright from Ref.^[28]. (C) Schematic of BIEF formation and Na⁺ storage mechanism upon discharge (left) and charge (right) of a Na-ion battery of Fe₂O₃/Na_0.67(Mn_0.67Ni_0.23Mg_0.1)O₂. Further comparison of BIEF-induced high-performance CFCs. Copyright from Ref.^[30]. (D) Band diagrams and alignment at Sm₂O₃/SmNi interface determined from UPS and UV-vis spectroscopy and schematic of proton transport process in SmNi. Copyright from Ref.^[31]. (E) BIEF-confined proton transport in CeO₂/CeO_2-δ core-shell structure and illustration of a proton conduction shuttle mechanism. Copyright from Ref.^[32].