An Ultrafast, Durable, and High‐Loading Polymer Anode for Aqueous Zinc‐Ion Batteries and Supercapacitors

Abstract

Zn metal has shown promise as an anode material for grid‐level energy storage, yet is challenged by dendritic growth and low Coulombic efficiency. Herein, an ultrafast, stable, and high‐loading polymer anode for aqueous Zn‐ion batteries and capacitors (ZIBs and ZICs) is developed by engineering both the electrode and electrolyte. The anode polymer is rationally prepared to have a suitable electronic structure and a large π‐conjugated structure, whereas the electrolyte is manufactured based on the superiority of triflate anions over sulfate anions, as analyzed and confirmed via experiments and simulations. This dual engineering results in an optimal polymer anode with a low discharge potential, near‐theoretical capacity, ultrahigh‐loading capability (≈50 mg cm−2), ultrafast rate (100 A g−1), and ultralong lifespan (one million cycles). Its mechanism involves reversible Zn2+/proton co‐storage at the carbonyl site. When the polymer anode is coupled with cathodes for both ZIB and ZIC applications, the devices demonstrate ultrahigh power densities and ultralong lifespans, far surpassing those of corresponding Zn‐metal‐based devices.

Kinetics‐Boosted Effect Enabled by Zwitterionic Hydrogel Electrolyte for Highly Reversible Zinc Anode in Zinc‐Ion Hybrid Micro‐Supercapacitors

“…[33,38] The C 1s spectrum exhibits characteristic peaks of CC (284.8 eV), CO/CN/CS (286.7 eV), OCO (288.7 eV), and CF (293.0 eV). [24,39,40] The N 1s spectrum is fitted with two components of CN + (400.2 eV) and NH 2 (402.5 eV). [41] Excellent mechanical properties of hydrogel electrolytes are essential to avoid premature failure of flexible devices caused by inevitable deformations in daily activities.…”

Stabilizing Interface pH by Mixing Electrolytes for High‐Performance Aqueous Zn Metal Batteries

“…When b is close to 1, the charge storage is mainly controlled by the surface capacitance process, while the typical diffusion process is dominant when b is close to 0.5. [35] As shown in Figure 6b, the b values for peaks 1, 2, 3, and 4 with 2 M 75% ZnSO 4 elec-trolyte are 0.70/0.83/0.60/0.70, indicating the coexistence of the capacitive and diffusion models during the charge storage process in Zn||MnO 2 full batteries (Figure S24, Supporting Information). Figure 6c summarizes the percentage of capacitive and diffusion contributions for different electrolytes at various sweep rates.…”

Polymerization increasing the capacitive charge storage for better rate performance: A case study of electrodes in aqueous sodium‐ion capacitors

“…As shown in Figure 3B, after 400 charge–discharge cycles, EDP remained with a capacitance of 428 F g −1 with a 92.2% retention of the initial capacitance, while PTCDA only delivered a capacitance of 80.5 F g −1 with retention of 42.3%. The better cycling performance of EDP might benefit from the rigid planar PDI moieties and the flexible ethylidene: The stacking of the conjugated planar PDI provides electron pathways and the flexible ethylidene prevented structure damages resulting from Na + insertion and/or the dissolution of its reductive product 33–35 …”