Hydrogel electrolytes for flexible energy storage devices commonly suffer from limited temperature tolerance and irreversible damage in chemical cross‐linked networks. Herein, a hydroxyl‐functionalized poly(ionic liquid) hydrogel electrolyte (M‐C/HIL‐PAM) is synthesized via one‐step γ‐ray‐induced copolymerization of acrylamide and 1‐(2,3‐dihydroxypropyl)‐3‐vinylimidazolium chloride in an aqueous NaClO 4 /Mg(ClO 4 ) 2 solution. Reversible hydrogen bonding and electrostatic interactions from hydroxyl and imidazolium groups create a dynamically reconfigurable network, endowing high toughness (tensile strength ~390 kPa, elongation at break ~2025%), strong adhesion, and efficient self‐healing. Meanwhile, the synergistic hydration effect of Na + and Mg 2+ disrupts the hydrogen‐bond network of water molecules, enabling stable ion transport at −70 to 60 °C. Benefiting from these properties, the resulting activated carbon || δ‐MnO 2 hybrid supercapacitor fabricated by in situ radiation polymerization operates across this wide temperature range. The device exhibits no capacity decay after 2000 cycles at −60 °C, retains good performance after 5000 cycles at room temperature and 60 °C, and withstands 3000 bending cycles without significant loss. Furthermore, the pouch supercapacitor shows negligible capacity decay after physical damage and rejoining, demonstrating intrinsic self‐healing ability. This work offers a promising strategy for designing wide‐temperature, mechanically robust, and self‐healable hydrogel electrolytes for flexible energy storage devices under extreme conditions.
The development of efficient functional materials for environmental and energy applications remains a significant challenge. Herein, we report a novel emulsion‐assisted oxidative polymerization strategy for synthesizing mesoporous poly(diaminonaphthalene) (PDAN) with uniform morphology and well‐defined mesopores. This method overcomes the rapid and uncontrolled polymerization kinetics associated with conventional oxidative routes, enabling the formation of small spherical nanoparticles with ordered mesopores. The resulting PDAN exhibits exceptional metal ion adsorption performance, particularly for Fe 3+ , demonstrating both high capacity and rapid kinetics that significantly surpass those of many previously reported polymer adsorbents. Moreover, the adsorbed Fe 3+ serves as a precursor for preparing nitrogen‐doped mesoporous carbon embedded with Fe 3 C nanoparticles (NCs‐Fe) through direct pyrolysis. The form of the iron species is the critical determinant of its oxygen reduction reaction (ORR) performance. The optimized NCs‐Fe catalyst demonstrates outstanding ORR activity, featuring a half‐wave potential of 0.88 V versus RHE, surpassing commercial 20 wt% Pt/C. When applied in zinc–air batteries, it delivers a high power density of 120 mW cm −2 and excellent cycling stability. This work presents a closed‐loop material design that integrates efficient metal ion capture with the fabrication of high‐performance ORR electrocatalysts.
Driven by rising demands for sustainable energy storage, rechargeable Li−ion batteries (LIBs) are required to deliver elevated energy density and extended service life. High‐nickel (Ni) layered oxides stand out as promising cathode candidates for next−generation LIBs. However, structural and interfacial instabilities of high‐Ni cathodes induce severe performance degradation during long−term cycling, particularly under high‐voltage operation. This review systematically summarizes and critically examines the degradation mechanisms of high‐Ni cathode materials, with particular emphasis on atomic−scale structural insights obtained through advanced characterization techniques. Drawing on previously reported characterization studies, we highlight the evolution of O3/O1 stacking configurations and associated surface and interfacial degradation, together with progressive phase deterioration during prolonged electrochemical cycling. We further compare the reported degradation behaviors of single−crystalline and polycrystalline high‐Ni cathodes, including stress–strain evolution, planar gliding defects, cracking, and related structural instabilities. In addition, recent progress in modification strategies for high‐voltage high‐Ni cathodes is critically reviewed, with particular emphasis on approaches that reinforce intrinsic structural stability. By integrating these mechanistic insights and mitigation strategies, this review provides perspectives and rational structural design guidelines for the development of high−performance high‐Ni cathodes for next−generation advanced LIBs.
Aqueous zinc-ion batteries (AZIBs) have attracted widespread attention as promising candidates for next-generation energy storage systems, owing to their inherent safety advantages, affordability, and eco-friendly characteristics. However, their development has been severely hindered by poor reversibility of the Zn metal and side reactions induced by the high water activity in aqueous electrolytes. Regulating the solvation structures of Zn ions (Zn2+) has emerged as an effective strategy to address these challenges. Herein, Zn-based laponite nanosheets (ZBL) were developed and used as an electrolyte additive. Especially, ZBL can be evenly dispersed in the electrolyte and effectively modulates the Zn2+ solvation structure, thereby promoting uniform Zn2+ stripping/plating and suppressing the corrosion of Zn anodes. As a result, a Zn||Zn symmetric cell with the addition of ZBL exhibits stable cycling exceeding 3200 h at a charge density of 5 mA cm-2 and a capacity of 1 mAh cm-2. Moreover, the ZBL-based Zn||vanadium pentoxide full cell exhibits good cycling stability over 3000 cycles at 2 A g-1 in coin cells and over 500 cycles at 1 A g-1 in pouch cells. These results highlight the significant potential of ZBL as an electrolyte additive for stable AZIBs.
Formation protocols dictate the nascent cathode-electrolyte interphase (CEI) and therefore the attainable energy density and lifetime of sulfide-based all-solid-state batteries (ASSBs). Yet, in contrast to liquid-electrolyte systems, the electro-chemo pathways activated during formation in ASSBs remain poorly defined and are rarely optimized with mechanistic intent. Herein, the formation protocol is positioned as an independent design variable that programs CEI passivation and establishes effective ion and electron transport pathways. Five distinct formation protocols are systematically evaluated to connect the initial cycling behavior with long-term cycling performance. A conventional constant voltage holding during the initial charge fails to passivate the CEI, leading to continued resistance buildup. Counterintuitively, elevated and dynamically modulated charge/discharge rates (C-rates) enable rapid and uniform CEI passivation. Most notably, turbo schedules that impose controlled high discharge current densities stabilize interfacial resistance and deliver durable cycling performance with substantially shortened formation time. Direct current internal resistance (DCIR) and average voltage evolution provide direct, operando-accessible descriptors of formation quality, generating a data stream readily usable for future AI-assisted, closed-loop protocol optimization. These results redefine formation from a manufacturing afterthought to a scalable strategy for engineering stable cathode interfaces in next-generation solid-state batteries.
