Influence of disodium ethylenediaminetetraacetate on zinc electrodeposition process and on the morphology, chemical composition and structure of the electrodeposits

Alkaline Ni-Zn Rechargeable Batteries for Sustainable Energy Storage: Battery Components, Deterioration Mechanisms, and Impact of Additives

The demand for long-term, sustainable, and low-cost battery energy storage systems with high power delivery capabilities for stationary grid-scale energy storage, as well as the necessity for safe lithium-ion battery alternatives, has renewed interest in aqueous zinc-based rechargeable batteries. The alkaline Ni-Zn rechargeable battery chemistry was identified as a promising technology for sustainable energy storage applications, albeit a considerable investment in academic research, it still fails to deliver the requisite performance. It is hampered by a relatively short-term electrode degradation, resulting in a decreased cycle life. Dendrite formation, parasitic hydrogen evolution, corrosion, passivation, and dynamic morphological growth are all challenging and interrelated possible degradation processes. This review elaborates on the components of Ni-Zn batteries and their deterioration mechanisms, focusing on the influence of electrolyte additives as a cost-effective, simple, yet versatile approach for regulating these phenomena and extending the battery cycle life. Even though a great deal of effort has been dedicated to this subject, the challenges remain. This highlights that a breakthrough is to be expected, but it will necessitate not only an experimental approach, but also a theoretical and computational one, including artificial intelligence (AI) and machine learning (ML).

Co-Solvent Electrolyte Engineering for Stable Anode-Free Zinc Metal Batteries

Anode-free metal batteries can in principle offer higher energy density, but this requires them to have extraordinary Coulombic efficiency (>99.7%). Although Zn-based metal batteries are promising for stationary storage, the parasitic side reactions make anode-free batteries difficult to achieve in practice. In this work, a salting-in-effect-induced hybrid electrolyte is proposed as an effective strategy that enables both a highly reversible Zn anode and good stability and compatibility toward various cathodes. The as-prepared electrolyte can also work well under a wide temperature range (i.e., from -20 to 50 °C). It is demonstrated that in the presence of propylene carbonate, triflate anions are involved in the Zn²⁺ solvation sheath structure, even at a low salt concentration (2.14 M). The unique solvation structure results in the reduction of anions, thus forming a hydrophobic solid electrolyte interphase. The waterproof interphase along with the decreased water activity in the hybrid electrolyte effectively prevents side reactions, thus ensuring a stable Zn anode with an unprecedented Coulombic efficiency (99.93% over 500 cycles at 1 mA cm^-2). More importantly, we design an anode-free Zn metal battery that exhibits excellent cycling stability (80% capacity retention after 275 cycles at 0.5 mA cm^-2). This work provides a universal strategy to design co-solvent electrolytes for anode-free Zn metal batteries.

Microbial Corrosion Resistance and Antibacterial Property of Electrodeposited Zn-Ni-Chitosan Coatings

Microbial corrosion is a universal phenomenon in salt water media such as seawater and wastewater environments. As a kind of efficient protective metal coating for steel, the damage of the Zn-Ni alloy coating was found to be accelerated under microbial corrosive conditions. To solve this problem, chitosan, which is considered a natural product with high antibacterial efficiency, was added to Zn-Ni electrolytes as a functional ingredient of electrodeposited Zn-Ni-chitosan coatings. It was found that the addition of chitosan significantly and negatively shifted the electrodeposition potentials and influenced the Ni contents, the phase composition, and the surface morphologies. By exposing the coatings in a sulfate-reducing bacteria medium, the microbial corrosion resistance was investigated. The results showed that compared to the Zn-Ni alloy coating, Zn-Ni-chitosan coatings showed obvious inhibiting effects on sulfate-reducing bacteria (SRB) and the corrosion rates of these coatings were mitigated to some degree. Further research on the coatings immersed in an Escherichia coli-suspended phosphate buffer saline medium showed that the bacteria attachment on the coating surface was effectively reduced, which indicated enhanced antibacterial properties. As a result, the Zn-Ni-chitosan coatings showed remarkably enhanced anticorrosive and antibacterial properties.

Synthesis and characterization of chitosan–zinc composite electrodeposits with enhanced antibacterial properties

Chitosan–zinc composite electrodeposits with enhanced broad-spectrum bactericidal property were successfully synthesized based on the chelation action for marine application.