Shallow-layer pillaring of a conductive polymer in monolithic grains to drive superior zinc storage via a cascading effect

Aqueous Zn metal batteries (ZBs) have obtained increasing attention recently owing to their low-cost and environmentally friendly nature. Unfortunately, the sluggish Zn(2+)de/intercalation in hosts often requires the nanostructural tailoring of cathode materials, which however degrades the tap density and accelerates the dissolution of active species. Herein, we propose a shallow-layer pillaring strategy to drive the superior zinc storage performance of V(2)O(5)monolithic grains without the prerequisite of intentional nanoscale attenuation. Thein situpolymerized 3,4-ethylenedioxythiophene chains only in the near-surface V(2)O(5)interlayers are sufficient to activate a cascading effect to successively open the deeper interlayers during Zn intercalation. This synergic interlayer expansion mechanism leads to a thorough and quick redox process of bulk phase V(2)O(5)even with micro-sized grains as opposed to the poor reaction kinetics in the non-pillared one. In contrast to excess pillaring or cation doping, the shallow-layer hybridization with a hydrophobic conductive polymer can suppress the dissolution of active species, reinforce the conductive contact between grains, lower the Zn(2+)diffusion barrier (0.39 eV) and absorption energy (0.17 eV), and upgrade the pseudocapacitance contribution (>67%) and Zn(2+)diffusion coefficient (1.43 x 10(-9)-1.81 x 10(-8)cm(2)s(-1)). This composite cathode enables an unprecedented cycling/rate performance (e.g.388, 367 and 351 mA h g(-1)even at 5, 8 and 10 A g(-1)respectively, and 269 mA h g(-1)after 4500 cycles at 10 A g(-1)), corresponding to high energy densities of 280.2 and 205.8 W h kg(-1)under ultrahigh power densities of 700.5 and 5960 W kg(-1), respectively. This concept of shallow-layer pillaring activation (especiallyviarich organic molecules) can be extended to more electrode systems with the preservation of the grain integrity.