Abstract
Polyzwitterionic hydrogel electrolytes with good anionic affinity and a well-aligned Zn(2+) deposition effect are regarded as potential alternatives for propelling zinc-ion batteries (ZIBs). However, their hydrophilic molecular chains show relatively low zincophility and easily transfer H(2)O molecules to the Zn surface, resulting in interfacial Zn corrosion and dendrites. Here we design highly zincophilic-hydrophobic polyzwitterionic hydrogel electrolyte (SC-PAM) via the crosslinking of zwitterionic sulfobetaine and carboxyl-rich carboxylated chitosan for ultrastable ZIBs. The zincophilic -SO(3) (-) motifs of zwitterionic sulfobetaine in SC-PAM afford highly Zn(2+)-selective migration channels and homogenize Zn(2+) flux with a high transference number of 0.90. Meanwhile, strong electronegative carboxyl groups (C[double bond, length as m-dash]O) in carboxylated chitosan strongly anchor H(2)O molecules via rich H-bonding interactions to establish a hydrophobic interfacial layer, which shields direct contact between H(2)O solvent and the Zn anode to avoid Zn corrosion. As a consequence, the Zn‖SC-PAM‖Cu cell exhibits a high average coulombic efficiency of 99.7% during 7600 cycles, while the Zn‖SC-PAM‖Zn cell shows ultrastable cycling exceeding 7500 hours. Significantly, SC-PAM can be further leveraged to design a state-of-the-art Zn‖SC-PAM‖V(2)O(5) full battery with high capacity (372 mAh g(-1)), large-current tolerance (15 A g(-1)), and ultralong cycle life (5000 cycles). This work extends the structural engineering landscape of zincophilic-hydrophobic polyzwitterionic hydrogel electrolytes for advanced ZIBs.