Rui Li

A dual-salt solubilization strategy breaks the solubility limits of Zn(Ac) ₂ and Zn(OTf) ₂ without inert solvents. The 6 m electrolyte suppresses the HER and dendrites, enabling 1500 hours cycling and close to 100% coulombic efficiency.

Aqueous zinc-ion batteries (AZIBs) with metallic Zn anodes face significant challenges including dendrite growth, low Zn utilization, and parasitic side reactions. Inspired by rocking-chair design of lithium-ion batteries, developing intercalative anodes offers a promising strategy to address these issues. However, existing anode materials exhibit limited diversity, high redox potentials (≥ 0.3 V vs. Zn²⁺/Zn), and low energy efficiency, constraining the development of rocking-chair zinc-ion batteries. Herein, we report protonated layered titanate (H₂Ti₃O₇) that demonstrates an ultra-low redox potential of 0.008 V vs. Zn²⁺/Zn. The anode delivers a reversible capacity of 78 mAh g^-1 at 0.2 A g^-1, along with superior rate performance and remarkable cycling stability. In situ XRD analysis reveals a two-phase reaction mechanism during Zn²⁺ (de)intercalation. When coupled with a zinc hexacyanoferrate (KZnHCF) cathode, the full cell achieves a high output voltage of 1.75 V, long-term cycling stability of 3000 cycles, and an exceptional energy efficiency of 87% that far exceeding commercial lead-acid batteries. This work provides a highly promising anode candidate for the realization of high-voltage, high-energy-efficiency, and dendrite-free AZIBs.

Prussian blue analogues (PBAs) show great promise as cathodes for aqueous sodium-ion batteries but suffer from severe structural degradation and sluggish kinetics. Herein, we develop an atomic layer deposition-driven interfacial engineering strategy to construct conformal Co₉S₈ nanocoatings (3-6 nm) on cobalt hexacyanoferrate (CoHCF) cathodes. Multiscale characterizations and theoretical calculations reveal that this artificial cathode-electrolyte interphase enhances electrochemical performance through a tripartite synergistic mechanism: (1) thermodynamic stabilization, which suppresses Fe dissolution by 85% through elevating Fe vacancy formation energy; (2) mechanical buffering, which alleviates mechanical strain by reducing lattice deformation by 59%; and (3) kinetic acceleration, which triggers a semiconductor-to-metal transition to boost electronic conductivity while accelerating Na⁺ diffusion, evidenced by a 1.5-order-of-magnitude increase in the minimum diffusion coefficient and a 38% reduction in the migration energy barrier. Consequently, the CoHCF@Co₉S₈-40//NaTi₂(PO₄)₃@C full batteries achieve exceptional capacity retention of 80.2% over 500 cycles (vs 3.8% for pristine counterparts), along with superior rate capabilities (72.0 mAh g^-1 vs 42.7 mAh g^-1 at 40 C, 1 C = 120 mA g^-1), outperforming most PBA-based cathodes. This work establishes a universal protocol for precision interfacial design in high-performance aqueous energy storage systems.

NASICON‐type Na ₃ V ₂ (PO ₄ ) ₃ (NVP) material possesses robust 3D structure and high sodium diffusivity, thus showcasing its immense potential in sodium‐ion batteries (SIBs). However, considering the perspective of environmental conservation, it is imperative to substitute vanadium with elements that are both cost‐effective and non‐toxic in order to further enhance its application in SIBs. Herein, Fe is utilized to replace the V site in the sodium vanadium phosphate structure and successfully prepared a pure phase sodium‐deficient NASICON (sodium superionic conductor) Na _3.15 VFe _0.86 (PO ₄ ) ₃ (NVFP‐650) cathode. It is found that the regulation of sintering temperature for Na _{3+ x} VFe(PO ₄ ) ₃ (NVFP) material can effectively mitigate the formation of secondary phases and enhance the electrochemical properties of the resulting product. The sodium‐deficient cathode shows enhanced electrochemical performance and sodium ion diffusion kinetics. It exhibits a high capacity of 102.8 mAh g ⁻¹ at 0.1 C, and exhibits a high‐capacity retention of 95.7% after 2000 cycles at 20 C. The energy storage mechanism and structural evolution are further investigated through SEM, TEM, XPS, and in situ XRD characterizations. The compositional modulation of sodium‐deficient NVFP and the elucidation of its cycling mechanisms in this work would provide valuable insights for enhancing the performance of sodium energy storage systems.

Aqueous iron‐ion batteries with reversible storage of Fe ²⁺ have undergone rapid development in recent years. Consistently throughout these studies, metallic iron is selected as the anode material. However, the large overpotential (250 mV) associated with the plating/stripping process of iron in aqueous solutions leads to unsatisfactory energy efficiency of the battery, although high capacity and Coulomb efficiency can be achieved. Herein, an iron‐free anode material, 9,10‐anthraquinone (AQ) is proposed in aqueous iron‐ion batteries, which shows a low reaction potential and minimal polarization during storing iron ions. The organic anode exhibits favorable specific capacity of 106 mAh g ⁻¹ at 0.5 A g ⁻¹ and excellent cycling stability (92.6% retention after 500 cycles). In addition, an aqueous full iron‐ion battery is constructed using AQ as the anode and 9,10‐phenanthraquinone (PQ) as the cathode. The full battery demonstrates an enhanced energy efficiency of 72%, which is 206% higher than that of metal iron anode, and shows excellent cycling stability and Coulombic efficiency. This work provides a viable route to overcome the high polarization of metallic iron anode and promote the development of aqueous iron‐ion batteries.

Top emission can enhance luminance, color purity, and panel-manufacturing compatibility for emissive displays. Still, top-emitting quantum-dot light-emitting diodes (QLEDs) suffer from poor stability, low light outcoupling, and non-negligible viewing-angle dependence because, for QLEDs with non-red emission, the electrically optimum device structure is incompatible with single-mode optical microcavity. Here, we demonstrate that by improving the way of determining reflection penetration depths and creating refractive-index-lowering processes, the issues faced by green QLEDs can be overcome. This leads to advanced device performance, including a luminance exceeding 1.6 million nits, a current efficiency of 204.2 cd A⁻¹, and a T₉₅ operational lifetime of 15,600 hours at 1000 nits. Meanwhile, our design does not compromise light outcoupling as it offers an external quantum efficiency of 29.2% without implementing light extraction methods. Lastly, an angular color shift of Δu’v’ = 0.0052 from 0° to 60° is achieved by narrowing the emission linewidth of quantum dots.

The low specific capacity determined by the limited electron transfer of p‐type cathode materials is the main obstruction to their application towards high‐performance aqueous zinc‐ion batteries (ZIBs). To overcome this challenge, boosting multi‐electron transfer is essential for improving the charge storage capacity. Here, as a typical heteroaromatic p‐type material, we unveil the unique reversible two‐electron redox properties of phenoxazine in the aqueous electrolytes for the first time. The second oxidation process is stabilized in the aqueous electrolytes, a notable contrast to its less reversibility in the non‐aqueous electrolytes. A comprehensive investigation of the redox chemistry mechanism demonstrates remarkably stable redox intermediates, including a stable cation radical PNO⋅⁺ characterized by effective electron delocalization and a closed‐shell state dication PNO²⁺. Meanwhile, the heightened aromaticity contributes to superior structural stability during the redox process, distinguishing it from phenazine, which features a non‐equivalent hybridized sp²‐N motif. Leveraging these synergistic advantages, the PNO electrodes deliver a high capacity of 215 mAh g⁻¹ compared to other p‐type materials, and impressive long cycling stability with 100 % capacity retention over 3500 cycles. This work marks a crucial step forward in advanced organic electrodes based on multi‐electron transfer phenoxazine moieties for high‐performance aqueous ZIBs.

The low specific capacity determined by the limited electron transfer of p‐type cathode materials is the main obstruction to their application towards high‐performance aqueous zinc‐ion batteries (ZIBs). To overcome this challenge, boosting multi‐electron transfer is essential for improving the charge storage capacity. Here, as a typical heteroaromatic p‐type material, we unveil the unique reversible two‐electron redox properties of phenoxazine in the aqueous electrolytes for the first time. The second oxidation process is stabilized in the aqueous electrolytes, a notable contrast to its less reversibility in the non‐aqueous electrolytes. A comprehensive investigation of the redox chemistry mechanism demonstrates remarkably stable redox intermediates, including a stable cation radical PNO⋅⁺ characterized by effective electron delocalization and a closed‐shell state dication PNO²⁺. Meanwhile, the heightened aromaticity contributes to superior structural stability during the redox process, distinguishing it from phenazine, which features a non‐equivalent hybridized sp²‐N motif. Leveraging these synergistic advantages, the PNO electrodes deliver a high capacity of 215 mAh g⁻¹ compared to other p‐type materials, and impressive long cycling stability with 100 % capacity retention over 3500 cycles. This work marks a crucial step forward in advanced organic electrodes based on multi‐electron transfer phenoxazine moieties for high‐performance aqueous ZIBs.

A high voltage aqueous full lithium-ion battery using novel Ti(HPO₄)₂·H₂O as the anode material with excellent stability.