Panthenol Additives with Multiple Coordination Sites Induce Uniform Zinc Deposition and Inhibited Side Reactions for High Performance Aqueous Zinc Metal Battery.

Application of aqueous zinc metal batteries (AZMBs) in large-scale new energy systems (NESs) is challenging owing to the growth of dendrites and frequent side reactions. Here, this study proposes the use of Panthenol (PB) as an electrolyte additive in AZMBs to achieve highly reversible zinc plating/stripping processes and suppressed side reactions. The PB structure is rich in polar groups, which led to the formation of a strong hydrogen bonding network of PB-H2O, while the PB molecule also builds a multi-coordination solvated structure, which inhibits water activity and reduces side reactions. Simultaneously, PB and OTF- decomposition, in situ formation of SEI layer with stable organic-inorganic hybrid ZnF2-ZnS interphase on Zn anode electrode, can inhibit water penetration into Zn and homogenize the Zn2+ plating. The effect of the thickness of the SEI layer on the deposition of Zn ions in the battery is also investigated. Hence, this comprehensive regulation strategy contributes to a long cycle life of 2300 h for Zn//Zn cells assembled with electrolytes containing PB additives. And the assembled Zn//NH4V4O10 pouch cells with homemade modules exhibit stable cycling performance and high capacity retention. Therefore, the proposed electrolyte modification strategy provides new ideas for AZMBs and other metal batteries.

Trigger a multi-electron reaction by tailoring electronic structure of VO2 toward more efficient aqueous zinc metal batteries.

VO2 (B) is recognized as a promising cathode material for aqueous zinc metal batteries (AZMBs) owing to its remarkable specific capacity and its unique, expansive tunnel structure, which facilitates the reversible insertion and extraction of Zn2+. Nonetheless, challenges such as the inherent instability of the VO2 structure, poor ion/electron transport and a limited capacity due to the low redox potential of the V3+/V4+ couple have hindered its wider application. In this study, we present a strategy to replace vanadium ions by doping Al3+ in VO2. This approach activates the multi-electron reaction (V4+/V5+), to increase the specific capacity and improve the structural stability by forming robust V5+O and Al3+O bonds. It also induces a local electric field by altering the local electron arrangement, which significantly accelerates the ion/electron transport process. As a result, Al-doped VO2 exhibits superior specific capacity, improved cycling stability, and accelerated electronic transport kinetics compared to undoped VO2. The beneficial effects of heterogeneous atomic doping observed here may provide valuable insights into the improvement electrode materials in metal-ion battery systems other than those based on Zn.

"Triple-synergistic effect" of K+ and PANI co-intercalation enabling the high-rate capability and stability of V2O5 for aqueous zinc-ion batteries.

Vanadium-based materials are widely recognized as the primary candidate cathode materials for aqueous Zn-ion batteries (AZIBs). However, slow kinetics and poor stability pose significant challenges for widespread application. Herein, to address these issues, alkali metal ions and polyaniline (PANI) are introduced into layered hydrated V2O5 (VO). Density functional theory calculations reveal that the synthesized (C6H4NH)0.27K0.24V2O5·0.92H2O (KPVO), with K+ and PANI co-intercalation, exhibits a robust interlayer structure and a continuous three-dimensional (3D) electron transfer network. These properties facilitate the reversible diffusion of Zn2+ with a low migration potential barrier and rapid response kinetics. The KPVO cathode exhibits a discharge specific capacity of 418.3 mAh/g at 100 mA/g and excellent cycling stability with 89.5 % retention after 3000 cycles at 5 A/g. This work provides a general strategy for integrating cathode materials to achieve high specific capacity and excellent kinetic performance.