Aqueous zinc batteries (AZBs) are often discussed as safer and more sustainable alternatives to lithium‐ion batteries. This comparison is important, but it may understate another distinctive value of AZBs, namely that they provide a comparatively accessible experimental platform for battery innovation. Because many AZB components can be handled in air and aqueous media, researchers can assemble cells, test ideas, and inspect failed devices without the infrastructure required for many nonaqueous batteries. Here, we argue that this practical accessibility is itself scientifically important. It allows AZBs to serve as a testing ground for ideas from electrochemistry, materials science, physics, engineering, and data science, while also lowering the entry barrier for early‐career researchers and groups entering battery research from adjacent fields.
The use of localized high‐concentration electrolytes (LHCEs) has emerged as a promising strategy to improve the stability of Li metal electrodes while overcoming the high viscosity and cost associated with high‐concentration electrolytes (HCEs). In this work, we investigate how electrolyte solvation structure and further physicochemical properties, like Li electrodeposition and SEI formation, evolve across a wide concentration range—from diluted electrolytes to HCEs and LHCEs—and how these changes influence Li reactivity and solid electrolyte interphase (SEI) formation in NCM ‖ Li cells. Ether‐based electrolytes composed of LiTFSI as conducting salt and 1,2‐dimethoxyethane (DME) as solvent are systematically modified using 1,1,2,2‐tetrafluoroethyl 2,2,3,3‐tetrafluoropropylether (TTE) as a non‐ion‐coordinating diluent to form LHCEs. Surface‐sensitive characterization, including time‐of‐flight secondary ion mass spectrometry, is employed to analyze the SEI composition. By correlating electrolyte concentration, solvation structure, and interfacial chemistry, this study focuses on the investigation of the Li metal surface after spontaneous formation of the SEI with the electrolytes and after electrodeposition/‐dissolution in Cu ‖ Li as well as high‐energy NCM ‖ Li cells.
Transition metal oxide (TMO)‐based aqueous zinc‐ion hybrid supercapacitors (ZIHSCs) have emerged as promising next‐generation energy‐storage systems that bridge the gap between batteries and supercapacitors by combining the high energy‐storage capability of battery‐type Zn anodes with the rapid charge–discharge characteristics of capacitor‐type or pseudocapacitive cathodes. Their intrinsic safety, environmental compatibility, and enhanced electrochemical performance make them promising alternatives for advanced energy‐storage applications. TMOs are widely investigated as cathode materials owing to their multiple oxidation states, rich redox activity, structural tunability, natural abundance, and high theoretical capacitance. However, their practical application remains constrained by poor electrical conductivity, structural instability, active‐material dissolution, and sluggish Zn 2+ diffusion kinetics. This review systematically summarizes recent advances in TMO‐based aqueous ZIHSCs, covering device configurations, Zn 2+ storage fundamentals, and charge‐storage mechanisms, particularly emphasizing on rational cathode design strategies, including nanostructure engineering, defect and vacancy modulation, and composite integration, to improve electrochemical performance. Furthermore, electrochemical charge‐storage mechanisms, Zn 2+ intercalation/deposition behavior, electrolyte optimization, and interfacial reaction kinetics are critically discussed. Finally, key challenges, including Zn dendrite growth, cathode degradation, and electrolyte instability, are highlighted, and future research directions are proposed. This review provides a comprehensive perspective and strategic framework for developing high‐performance TMO‐based aqueous ZIHSCs for next‐generation energy‐storage applications.
Overcoming the slow reaction rate of TiO 2 anodes is crucial for achieving high‐rate lithium storage. In this study, we designed a hollow TiO 2 spherical anode with dual‐carbon coating and Ni doping to address the low electrical conductivity and slow Li + diffusion of TiO 2 . Ultrathin titanate nanosheets were assembled onto a polymer template, coated with a bimetallic Zn/Ni zeolitic imidazolate framework and glucose, and then pyrolyzed to obtain TiO 2 /ZnNi–NC/C hollow spheres. This structure features a grain boundary‐rich mixed‐phase TiO 2 framework, with an inner (N‐doped) and an outer (glucose‐derived) carbon layer. Ni incorporation is associated with increased carbon ordering, consistent with a proposed role in improving electronic connectivity within the carbon framework. The TiO 2 /ZnNi–NC/C‐HS material exhibits high reversible capacity and excellent rate performance, maintaining a higher capacity than TiO 2 ‐HS at 1 A g −1 and exhibiting a capacity retention of >99% over 1000 cycles. Control experiments confirmed that both nickel doping and the double carbon layer play important roles in the performance enhancement, and their synergistic effect enables fast and stable lithium storage within TiO 2 . Hence, this study highlights the potential of combining MOF‐derived architectures with metal‐catalyzed carbon matrices to develop next‐generation lithium‐ion battery anodes that simultaneously deliver high capacity and high‐power performance.
Silicon oxycarbide (SiOC) has emerged as a promising anode material for next‐generation lithium‐ion batteries owing to its structural stability and ability to accommodate large amounts of lithium. However, its practical application is often limited by insufficient electronic conductivity and poor electrochemical utilization of active silicon‐rich domains, particularly under high‐rate operation. In this work, we report a surface‐engineering strategy in which synthesized silicon‐rich SiOC is integrated with chemically modified reduced graphene oxide (rGO) through a facile freeze‐drying process to construct a highly conductive Si‐rich SiOC‐rGO composite anode. The achieved electrochemical performance surpasses that of many previously reported doped SiOC anodes, highlighting surface‐engineered silicon‐rich SiOC‐rGO composites as an attractive alternative to more complex compositional modification strategies. The interconnected rGO network enhances electronic transport, facilitates charge‐transfer kinetics, and promotes efficient utilization of the active silicon‐rich phase while maintaining the structural integrity of the SiOC matrix during repeated lithiation/delithiation. As a result, the SiOC‐rGO composite delivers substantially improved electrochemical performance compared with pristine Si‐rich SiOC, exhibiting high reversible specific capacity, excellent rate capability, and remarkable long‐term cycling stability. Notably, the composite retains a capacity of ~600 mAh g −1 at a high rate of 2 C after 1000 cycles, demonstrating outstanding durability under demanding operating conditions.
