Nonionic Surfactant Coconut Diethanol Amide Inhibits the Growth of Zinc Dendrites for More Stable Zinc-Ion Batteries

Abstract

Uncontrollable growth of zinc dendrites and byproducts has become the main factor which limits the life of zinc-ion batteries. Herein, we reported a nonionic surfactant, coconut diethanolamide (CDA), which can be applied as an electrolyte additive. It not only effectively suppresses zinc graft growth and promotes uniform growth of zinc dendrites but also efficiently inhibits the generation of side reactions and byproducts. When CDA is added to the electrolyte, the life of the battery has been significantly improved (1580 h). Compared with an electrolyte without CDA (100 h), its life has grown more than 10 times. CDA can adsorb on the surface of the zinc electrode to form a protective layer by its special molecular structure. Therefore, zinc ions will have a higher barrier for deposition, and there should be induced uniform deposition. Moreover, the Cu/Zn cell shows 98% average Coulomb efficiency in the electrolyte with CDA after about 620 h. In addition, after long-term cycles, the addition of CDA enables the MnO2/Zn cell to show 85% capacity retention and 98% average Coulomb efficiency. The electrolyte additives reported in this study will provide a more convenient and environmentally friendly way to effectively solve the problem of zinc branches.

Nonionic Surfactant-Assisted In Situ Generation of Stable Passivation Protective Layer for Highly Stable Aqueous Zn Metal Anodes

“…Five weight percent PEGTE can form a large number of micelles, which is confirmed by the Tyndall effect (Figure S2). At the solid–liquid interface, the PEGTE micelles can guild the honeycomb-like Zn deposition at the surface of Zn foil through the interaction with the solvated zinc ions in the initial deposition stage. , Those are different from previously reported surfactants, such as TBA 2 SO 4 and coconut diethanolamide (CDA) . The honeycomb-like surface Zn is further oxidized by the dissolved O 2 in the electrolyte to form a very thin ZnO passivation protective layer because of its high surface area, as shown in Figure b.…”

“…52,53 Those are different from previously reported surfactants, such as TBA 2 SO 4 54 and coconut diethanolamide (CDA). 55 The honeycomb-like surface Zn is further oxidized by the dissolved O 2 in the electrolyte to form a very thin ZnO passivation protective layer because of its high surface area, as shown in Figure 1b. Benefit from its unique hierarchical structure, the inert H-ZnO protection layer can enable the homogeneous and dense Zn deposition underneath the protection layer, as shown in Figure S3.…”

Dendrite-free Zn anode enabled by anionic surfactant-induced horizontal growth for highly-stable aqueous Zn-ion pouch cells

“…Surfactants are a class of electrolyte additives that are often used to control Zn deposition and surface reactions in AZIBs. [17][18][19][20][21] Nevertheless, only few reports focused on the use of surfactants to guide the preferential deposition of Zn 2+ in the (002) orientation and simultaneously suppress the side reactions. Herein, we introduce a common anionic surfactant, sodium 3,3 0dithiodipropane sulfonate (denoted as SPS; see Fig.…”

Synergistically Stabilizing Zinc Anodes by Molybdenum Dioxide Coating and Tween 80 Electrolyte Additive for High-Performance Aqueous Zinc-Ion Batteries

“…Thus, Zn anodes suffer from poor electrochemical stability, low Coulombic efficiency (CE), short circuits, and limited cycle life, restricting the practical development of ZIBs . Various strategies have been proposed to address these issues of Zn anodes, including modifying the anode surface, , optimizing the electrolyte composition, , constructing 3D-structured or alloyed anodes, , and fabricating functional separators. , Among them, the coating and electrolyte engineering strategies offer great potential for the practical application of Zn-ion batteries.…”

“…The exfoliation of the coating layer could occur during cycling due to the poor affinity between protective materials and Zn substrates. Furthermore, electrolyte optimization can suppress Zn anode issues, especially by adding various additives to the electrolyte. ,, In view of practical applications, the use of an electrolyte additive is a facile method to regulate the Zn anode-electrolyte interface. Adding additives can also stabilize Zn ions in electrolytes, and a homogeneous nucleation process can be achieved by the control of electrode–electrolyte interfaces due to the additives .…”