Ion‐Selective Pumping and Entropy‐Driven Lithium Transport in Composite Electrolytes via Dynamic Competitive Coordination for All‐Solid‐State Batteries

Abstract Polyethylene oxide (PEO) electrolytes face limitations like low ionic conductivity, poor kinetics, and Li dendrite growth. Within this context, a novel solid‐state electrolyte (SSE) integrates Prussian blue (PB) 3D open framework into a PEO matrix. This design capitalizes on PB uniformly distributed Fe─N≡C sites to establish a bio‐inspired “ion‐selective pumping” effect through dynamic competitive coordination with PEO ether groups (analogous to cellular K + /Na + pumps). The PB framework selectively anchors TFSI − while its electron‐deficient Fe 3+ /Fe 2+ sites promote lithium salt dissociation via Lewis's acid‐base interactions, forcibly stripping Li⁺ from solvation shells into migration pathways. Furthermore, the 3D interconnected nanochannels (15.89 nm) synergize with PEO amorphous regions to create gradient‐pore topological channels. The disorder‐order interfaces at PB‐PEO boundaries induce localized entropy enhancement ( ΔS ↑), thermodynamically driving spontaneous Li + migration through Gibbs free energy minimization. This multi‐scale architecture enables stable Li + deposition/stripping by providing an abundant migration pathway. As a result, Li/PEO@1%PB/Li cells exhibit excellent cycling stability over 2000 h at 0.2 mAh·cm −2 and 6000 h at 0.1 mAh·cm −2 . Li/PEO@1%PB/LFP cells retain 90% capacity after 1000 cycles at 1C. This study offers a new strategy combining ionic coordination and 3D channel design to advance high‐performance all‐solid‐state lithium metal batteries (ASSLMBs).