Tuning the Metal Ions of Prussian Blue Analogues in Separators to Enable High-Power Lithium Metal Batteries

Abstract

The Li dendrite issue is the major barrier that limits the implement of Li metal anode practically, especially at high current density. From the perspective of the nucleation and growth mechanism of the Li dendrite, we rationally develop a novel Prussian blue analogues (PBA)-derived separator, where tuning the metal ions bestows the PBAs with open metal site to confine anion movement and thereby afford a high Li + transference number (0.78), and PBA with ordered micropores could act as an ionic sieve to selectively extract Li + and thereby homogenize Li + flux. This demonstrates a highly reversible Li plating/stripping cycling for 3000 h at a practically high current density (5.0 mA cm −2 ). Consequently, a high loading Li||LiFeO 4 battery (∼10.0 mg cm −2 ) demonstrates ultralong cycling life at high current densities (∼5.1 mA cm −2 ). This work highlights the prospect of optimizing PBAs in regulating ion transport behavior to enable high-power Li metal batteries.

Zwitterionic Covalent Organic Framework Based Electrostatic Field Electrocatalysts for Durable Lithium–Sulfur Batteries

“…In addition to resolving the shuttle effect of LiPSs, the separator modification strategy can also guide the ion-conduction behavior in the electrolyte. , Especially for a charged separator, the dissociation of ion pairs under the electric field always promotes the Li + transport. , The Li + transference number and ionic conductivity are two important parameters reflecting the ion-conduction behavior. As shown in Figure a and Figure S16, the Li + transference number of the zwitterionic COF separator (0.94) is prominently higher than that of the anionic COF separator (0.75), cationic COF separator (0.76), and pristine PP separator (0.54).…”

“…Generally, anionic substrates create a negative electric field for repulsing polysulfides, such as Nafion, 29,30 sulfonated acetylene black, 31 styrene sulfonate 32 and caffeic acid, 33 while cationic substrates act as an adsorbent for trapping polysulfides, such as polyquaternium-10, 34 layered double hydroxides, 35 tetraethylammonium nitrate 36 and Prussian blue analogues. 37 However, the catalytic performance based on electrostatic interactions is still rarely studied, especially for bidirectional catalysis.…”

“…Unlike point-to-point interactions between LiPSs and traditional polar catalysts, electrostatic interactions create more extensive local electric fields to affect the conversion behavior of LiPSs, which improves the catalytic efficiency and reduces the possibility of catalyst passivation. ,,− Electrostatic interactions can be divided into electrostatic repulsion and attraction. Generally, anionic substrates create a negative electric field for repulsing polysulfides, such as Nafion, , sulfonated acetylene black, styrene sulfonate and caffeic acid, while cationic substrates act as an adsorbent for trapping polysulfides, such as polyquaternium-10, layered double hydroxides, tetraethylammonium nitrate and Prussian blue analogues . However, the catalytic performance based on electrostatic interactions is still rarely studied, especially for bidirectional catalysis.…”

Molecular-Level Anion and Li+ Co-Regulation by Amphoteric Polymer Separator for High-Rate Stable Lithium Metal Anode

“…As a result, the local space charge attracts a large number of Li + to maintain electrical neutrality, resulting in the early lithium dendrite growth. 24,31 Therefore, a high t Li + value is regarded as crucial for low internal resistance and mitigated lithium dendrite growth.…”

The Inducement and “Rejuvenation” of Li Dendrites by Space Confinement and Positive Fe/Co‐Sites

“…In consideration of the pivotal role of separator in cell configuration serving as electrolyte reservoir and providing ion transport pathway, the decoration of commercial separator with unique nanostructured materials suggests an economically convenient strategy to achieve modulated Li + transport as demonstrated by the recently reported researches. The investigation of FeCo‐PBA as modifier to decorate commercial separator for LMB has been rarely reported to the best of our knowledge, although NiFe‐, [ 36 ] FeFe‐, [ 37,38 ] and NiCo‐PBA [ 36 ] derived separators have been thoroughly studied. This offers an ideal opportunity to simultaneously realize Li + nucleation guidance and active the inactive dendrites or “dead” Li.…”