Ultrahigh Loading Electrode in High-Energy-Density Lithium Batteries In their Research Article (DOI: 10.1002/adma.202506266), Soojin Park, Youn Soo Kim, and co-workers design an ionically conductive elastic polymer (ICEP) binder that is introduced for fabricating ultrahigh mass-loading NCM811 cathodes, offering enhanced elasticity, adhesion, and ionic conductivity for improved structural and interfacial stability. The cathode, with 62.5 mg cm−2 (12.7 mAh cm−2), delivers 377.6 Wh kgcell−1/1016.8 Wh Lcell−1 (including packaging) when paired with Li metal anodes, demonstrating excellent electrochemical stability.

Self-regulating hydrogels represent the next generation in the development of soft materials with active, adaptive, autonomous, and intelligent behavior inspired by sophisticated biological systems. Nature provides exemplary demonstrations of such self-regulating behaviors, including muscle tissue's precise biochemical and mechanical feedback mechanisms, and coordinated cellular chemotaxis driven by dynamic biochemical signaling. Building upon these natural examples, self-regulating hydrogels are capable of spontaneously modulating their structural and functional states through integrated negative feedback loops. In this review, the key design principles and implementation strategies for self-regulating hydrogel actuators are comprehensively summarized. We first systematically classify self-regulating hydrogels into sustained regulation, involving continuous modulation cycles under constant stimuli and one-cycle regulation, characterized by transient transitions driven by specific chemical fuels. Thereafter, the underlying mechanisms, types of hydrogels used, fuels, oscillation periods, amplitudes, and potential applications are highlighted. Finally, current scientific challenges and future opportunities for enhancing the robustness, modularity, and practical applicability of self-regulating hydrogel actuators are discussed. This review aims to provide structured guidelines and inspire interdisciplinary research to further develop advanced hydrogel-based regulatory systems for applications such as soft robotics, autonomous sensors, responsive biomedical devices, and adaptive functional materials.

Extraneural Electrodes In article number 2203431, Youn Soo Kim and co-workers introduce an ideal conductive hydrogel for tissue-like extraneural electrodes with high conformability to improve the tissue–electronic interface. This hydrogel exhibits excellent adhesion, biocompatibility, non-swelling, and electrical conductivity in water. The hydrogel is implanted into the sciatic nerve of rats, and neuromodulation is successfully demonstrated through low-current electrical stimulation.

Gel polymer electrolytes (GPEs) are promising for aqueous zinc-ion batteries (AZIBs), with in situ GPEs offering improved interfacial contact. However, conventional in situ GPEs require initiators and crosslinkers, which can cause Zn corrosion and ion-trapping effects. Here, we report a zwitterionic in situ GPE that self-polymerization at room temperature without initiators or crosslinkers, enabling uniform Zn plating/stripping. The symmetric cell exhibits remarkable stability, sustaining over 4,000 hours at 0.5 mAh cm⁻² and 0.5 mA cm⁻². A Zn|Zn 0.25 V 2 O 5 full cell further confirms excellent electrochemical performance without side reactions, demonstrating the potential of this system for next-generation AZIBs.

Abstract The growing demand for high‐energy‐density lithium‐ion batteries (LIBs) has spurred interest in silicon (Si)‐based anodes, but their practical use is hindered by volumetric expansion during cycling, leading to electrode degradation and uncontrolled solid electrolyte interphase (SEI) growth. Here, a molecularly engineered approach is presented to regulate Coulomb interactions in coacervate charged polymer binders for stabilizing Si anodes. By systematically tuning effective charge density through different functional groups, electrostatic interactions within the binder network are modulated to optimize adhesion, mechanical integrity, and electrochemical performance. Four charged polymers with varying functional groups: amine (A), guanidine (G), sulfonate (S), and carboxylate (C) are synthesized and studied. The G‐C binder, exhibiting the strongest Coulomb interaction, demonstrated superior adhesion, mechanical stability, and cycling performance. This binder enabled the fabrication of ultra‐high areal capacity Si‐based electrodes (12.2 mAh cm −2 ), outperforming previously reported binder systems. Moreover, full‐cell evaluations of Si‐based anodes with G‐C binders and Ni‐rich layered cathodes demonstrated stable cycling at high areal capacities (4.7 mAh cm −2 ), underscoring the practical viability of this approach. These findings establish Coulomb interactions as a key design parameter for next‐generation polymer binders, offering a promising strategy to address the long‐standing challenges of Si‐based anodes in LIBs.

Glycol-based polymer gels have emerged as stable alternatives to water-based hydrogels, offering intrinsic advantages owing to the ultra-low volatility and high thermal stability of glycol solvents. However, progress has been limited by persistent challenges in simultaneously achieving both long-term mechanical reliability and strong interfacial adhesion under ambient and extreme conditions. Here, we report a strategy to overcome these limitations by selectively evaporating water from poly(2-hydroxyethyl acrylate) gels prepared in water-glycol co-solvent systems. This controlled drying induces predominantly affine shrinkage, preserving the polymer network's elastic modulus while substantially increasing elongation at break and minimizing mechanical hysteresis during cyclic loading. Moreover, evaporation-driven enrichment of hydroxyl groups at the gel surface yields a more than sixfold increase in interfacial adhesion strength. As a result, the optimized glycol gels maintain robust mechanical performance and strong adhesion across an exceptionally broad temperature range (-20 °C to 120 °C). In contrast, conventional hydrogels collapse and lose adhesion at these extreme temperatures. These findings establish a practical design paradigm for thermally stable polymer gels, thereby paving the way for long-term biomedical adhesives and wearable electronics.

Quasi-solid-state batteries (QSSBs) are attracting considerable interest as a promising approach to enhance battery safety and electrochemical performance. However, QSSBs utilizing high-capacity active materials with substantial volume fluctuations, such as Si microparticle (SiMP) anodes and Ni-rich cathodes (NCM811), suffer from unstable interfaces due to contact loss during cycling. Herein, an in situ interlocking electrode-electrolyte (IEE) system is introduced, leveraging covalent crosslinking between acrylate-functionalized interlocking binders on active materials and crosslinkers within the quasi-solid-state electrolyte (QSSE) to establish a robust, interconnected network that maintains stable electrode-electrolyte contact. This IEE system addresses the limitations of liquid electrolyte and QSSE configurations, evidenced by low voltage hysteresis in (de)lithiation peaks over 200 cycles, stable interfacial resistance throughout cycling, and the absence of void formation. A pressure-detecting cell kit further confirms that the IEE system exhibits lower pressure changes during cycling without any voltage fluctuations from contact loss. Moreover, the SiMP||NCM811 full cell with the IEE system demonstrates superior electrochemical performance, and a bi-layer pouch cell configuration achieves an impressive energy density of 403.7 Wh kg^-1/1300 Wh L^-1, withstanding mechanical abuse tests such as folding and cutting, providing new insights into high-energy-density QSSBs.

Abstract Aqueous zinc ion batteries (AZIBs) have emerged as a promising next‐generation energy storage technology to replace lithium‐ion batteries. Recently, gel polymer electrolytes (GPEs), as a critical component of AZIBs, have garnered significant attention due to their potential to address challenges associated with conventional aqueous electrolytes, such as dendrite growth, corrosion, electrolyte evaporation, and leakage. However, the mechanical properties of hydrogels often remain suboptimal due to inherent limitations. This review focuses on the mechanical requirements that GPEs must meet for practical implementation in AZIBs. Furthermore, it highlights various gel design strategies to achieve superior mechanical performance, including double‐network (DN) gels, topological gels, and other advanced gel network architectures. Promising directions and rational perspectives for future research are also proposed, offering insights into the development of high‐performance GPEs for AZIBs.

Thermoresponsive hydrogel microcapsules have received considerable attention as controlled release systems due to their tunable molecular permeability. However, conventional microcapsules based on swelling/deswelling transition often suffer from poor mechanical properties as well as limited range of molecular cut‐off tunability, restricting their practical use. In this work, thermal phase separation in hydrogel microcapsules is introduced to achieve mechanical toughening as well as broad range of control over molecular permeability. By using poly(acrylic acid) (PAAc) hydrogels ionically crosslinked with calcium/acetate ions as the microcapsule shell, a polymer dense state can be induced upon heating above the transition temperature. Compression tests and dye permeation studies demonstrate a significant increase in modulus as well as substantial reduction in molecular cut‐off threshold upon phase separation. Moreover, it is demonstrated that the release profile of the encapsulated substances can be programmed by adjusting the duration of thermal exposure, which governs the recovery kinetics of the hydrogel network. The showcased phase separation‐induced strategy enables unprecedented control of the molecular permeability and significant enhancement in mechanical properties of the hydrogel microcapsules, offering a new avenue in the design of advanced stimuli‐responsive microcapsules.

Ultrahigh Loading Electrode in High-Energy-Density Lithium Batteries In their Research Article (DOI: 10.1002/adma.202506266), Soojin Park, Youn Soo Kim, and co-workers design an ionically conductive elastic polymer (ICEP) binder that is introduced for fabricating ultrahigh mass-loading NCM811 cathodes, offering enhanced elasticity, adhesion, and ionic conductivity for improved structural and interfacial stability. The cathode, with 62.5 mg cm−2 (12.7 mAh cm−2), delivers 377.6 Wh kgcell−1/1016.8 Wh Lcell−1 (including packaging) when paired with Li metal anodes, demonstrating excellent electrochemical stability.

Self-regulating hydrogels represent the next generation in the development of soft materials with active, adaptive, autonomous, and intelligent behavior inspired by sophisticated biological systems. Nature provides exemplary demonstrations of such self-regulating behaviors, including muscle tissue's precise biochemical and mechanical feedback mechanisms, and coordinated cellular chemotaxis driven by dynamic biochemical signaling. Building upon these natural examples, self-regulating hydrogels are capable of spontaneously modulating their structural and functional states through integrated negative feedback loops. In this review, the key design principles and implementation strategies for self-regulating hydrogel actuators are comprehensively summarized. We first systematically classify self-regulating hydrogels into sustained regulation, involving continuous modulation cycles under constant stimuli and one-cycle regulation, characterized by transient transitions driven by specific chemical fuels. Thereafter, the underlying mechanisms, types of hydrogels used, fuels, oscillation periods, amplitudes, and potential applications are highlighted. Finally, current scientific challenges and future opportunities for enhancing the robustness, modularity, and practical applicability of self-regulating hydrogel actuators are discussed. This review aims to provide structured guidelines and inspire interdisciplinary research to further develop advanced hydrogel-based regulatory systems for applications such as soft robotics, autonomous sensors, responsive biomedical devices, and adaptive functional materials.