Wearable transdermal iontophoresis eliminating the need for external power sources offers advantages for patient-comfort when deploying epidermal diseases treatments. However, current self-powered iontophoresis based on energy harvesters is limited to support efficient therapeutic administration over the long-term operation, owing to the low and inconsistent energy supply. Here we propose a simplified wearable iontophoresis patch with a built-in Mg battery for efficient and controllable transdermal delivery. This system decreases the system complexity and form factors by using viologen-based hydrogels as an integrated drug reservoir and cathode material, eliminating the conventional interface impedance between the electrode and drug reservoir. The redox-active polyelectrolyte hydrogel offers a high energy density of 3.57 mWh cm⁻², and an optimal bioelectronic interface with ultra-soft nature and low tissue-interface impedance. The delivery dosage can be readily manipulated by tuning the viologen hydrogel and the iontophoresis stimulation mode. This iontophoresis patch demonstrates an effective treatment of an imiquimod-induced psoriasis mouse. Considering the advantages of being a reliable and efficient energy supply, simplified configuration, and optimal electrical skin-device interface, this battery-powered iontophoresis may provide a new non-invasive treatment for chronic epidermal diseases.

Aqueous all‐polymer proton batteries (APPBs) consisting of redox‐active polymer electrodes are considered safe and clean renewable energy storage sources. However, there remain formidable challenges for APPBs to withstand a high current rate while maximizing high cell output voltage within a narrow electrochemical window of aqueous electrolytes. Here, a capacitive‐type polymer cathode material is designed by grafting poly(3,4‐ethylenedioxythiophene) (PEDOT) with bioinspired redox‐active catechol pendants, which delivers high redox potential (0.60 V vs Ag/AgCl) and remarkable rate capability. The pseudocapacitive‑dominated proton storage mechanism illustrated by the density functional theory (DFT) calculation and electrochemical kinetics analysis is favorable for delivering fast charge/discharge rates. Coupled with a diffusion‐type anthraquinone‐based polymer anode, the APPB offers a high cell voltage of 0.72 V, outstanding rate capability (64.8% capacity retention from 0.5 to 25 A g⁻¹), and cycling stability (80% capacity retention over 1000 cycles at 2 A g⁻¹), which is superior to the state‐of‐the‐art all‐organic proton batteries. This strategy and insight provided by DFT and ex situ characterizations offer a new perspective on the delicate design of polymer electrode patterns for high‐performance APPBs.

Metallic interface engineering is a promising strategy to stabilize Zn anode via promoting Zn²⁺ uniform deposition. However, strong interactions between the coating and Zn²⁺ and sluggish transport of Zn²⁺ lead to high anodic polarization. Here, we present a bio-inspired silk fibroin (SF) coating with amphoteric charges to construct an interface reversible electric field, which manipulates the transfer kinetics of Zn²⁺ and reduces anodic polarization. The alternating positively and negatively charged surface as a build-in driving force can expedite and homogenize Zn²⁺ flux via the interplay between the charged coating and adsorbed ions, endowing the Zn-SF anode with low polarization voltage and stable plating/stripping. Experimental analyses with theoretical calculations suggest that SF can facilitate the desolvation of [Zn(H₂O)₆]²⁺ and provide nucleation sites for uniform deposition. Consequently, the Zn-SF anode delivers a high-rate performance with low voltage polarization (83 mV at 20 mA cm⁻²) and excellent stability (1500 h at 1 mA cm⁻²; 500 h at 10 mA cm⁻²), realizing exceptional cumulative capacity of 2.5 Ah cm⁻². The full cell coupled with Zn_xV₂O₅·nH₂O (ZnVO) cathode achieves specific energy of ~ 270.5/150.6 Wh kg⁻¹ (at 0.5/10 A g⁻¹) with ~ 99.8% Coulombic efficiency and retains ~ 80.3% (at 5.0 A g⁻¹) after 3000 cycles.

The use of silicon (Si) as a lithium-ion battery’s (LIBs) anode active material has been a popular subject of research, due to its high theoretical specific capacity (4200 mAh g⁻¹). However, the volume of Si undergoes a huge expansion (300%) during the charging and discharging process of the battery, resulting in the destruction of the anode’s structure and the rapid decay of the battery’s energy density, which limits the practical application of Si as the anode active material. Lithium-ion batteries’ capacity, lifespan, and safety can be increased through the efficient mitigation of Si volume expansion and the maintenance of the stability of the electrode’s structure with the employment of polymer binders. The main degradation mechanism of Si-based anodes and the methods that have been reported to effectively solve the Si volume expansion problem firstly are introduced. Then, the review demonstrates the representative research work on the design and development of new Si-based anode binders to improve the cycling stability of Si-based anode structure from the perspective of binders, and finally concludes by summarizing and outlining the progress of this research direction.