fig4

Figure 4. (A) Schematic diagram and (B) SEM image of the NaHCO₃ crystal coated with MCs using a directional freeze-drying process without carbonisation. (C) Rate capability profiles of WPCS and MCC electrodes. (D) Cycling performance at a current density of 5 A·g^-1 (reprinted with permission^[61]). (E) Synthesis route of non-conjugated poly(carbonylpyridinium)s (NCP1 and NCP2). (F) Galvanostatic charge/discharge curves of NCP2 electrode at 0.1 A·g^-1. (G) Rate performance of NCP2 for NIBs and PIBs at different current densities (reprinted with permission^[62]). (H) Schematic illustration of the synthesis process and (I) the carbon interlayer on the separator to capture shuttled species. (J) K-S battery system in the voltage range of 0.5-3.0 V. (K) Schematic illustration of efficient and self-protectable functions of this leaf-bio-inspired structure (reprinted with permission^[63]).