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

Abstract

A highly stable interface for aqueous rechargeable Zn batteries is of importance to inhibit the growth of Zn dendrites and suppress the side reactions. In this work, we have developed a stable honeycomb-like ZnO passivation protective layer on the Zn surface, which is in situ generated with the assistance of a nonionic surfactant additive (polyethylene glycol tert-octylphenyl ether, denoted as PEGTE). The ZnO passivation layer can facilitate the uniform distribution of the electric field, guiding the uniform deposition of Zn2+ and inhibit the generation of dendrites. As a result, the symmetric cell using the electrolyte with PEGTE shows an excellent performance at high areal capacity, reflected by stable cycling for over 2400 h at 5 mAh/cm2 and 1300 h at 10 mAh/cm2. The full cell paired with V2O5 demonstrates a long lifespan for more than 600 cycles at a low negative/positive capacity ratio.

. Insights into the design of mildly acidic aqueous electrolytes for improved stability of Zn anode performance in zinc-ion batteries

“…Organic additives have better water solubility than inorganic additives and are thus widely studied. Organic additives can be further classified into organic small molecule additives [37,70,87] and organic polymer additives [71,83,84,157,158] . Compared with organic polymer additives, organic small molecule additives have been more intensively studied due to their diversity, simple structure, ease of synthesis, and pro-environment.…”

Functionalized Separator Strategies toward Advanced Aqueous Zinc‐Ion Batteries

“…[14,15] In addition, the dendrite growth, passivation, corrosion, and hydrogen evolution on the zinc anode side result in a short service time and large polarization of the zinc anode. [16][17][18][19] Various solutions have been proposed for the above-mentioned problems of the anode and cathode of ZIBs, such as surface protection of zinc anodes, [20][21][22][23] design of zinc deposition substrates, [24] electrolyte modification, [25] and cathode coating strategies. [26,27] The functionalized separator strategy is recognized as a straightforward and efficient method for improving the electrochemical performance of both the cathode and the anode, leading to high energy/ power density and long service life of ZIBs.…”

Simultaneous Inhibition of Zn Dendrites and Polyiodide Ions Shuttle Effect by an Anion Concentrated Electrolyte Membrane for Long Lifespan Aqueous Zinc–Iodine Batteries

“…On the Zn metal anode side, uncontrollable zinc dendrite growth and side reactions will lead to poor cycling stability and eventually internal shortcircuit. 23,24 On the other hand, insoluble I 2 in the cathode tends to combine with I − to form soluble polyiodide ions (I 3 − and I 5 − anions) into the electrolyte, leading to self-discharge and overcharge issues with unsatisfactory Coulombic efficiency. 22,25 More severely, the shuttle effect of intermediate polyiodide ions will react with anode materials, leading to the irreversible loss of cathode active materials and self-corrosion of Zn metal anodes, deteriorating the whole electrochemical performance of Zn−I 2 batteries dramatically.…”

“…In spite of the outstanding adaptability for large-scale energy storage, there are still significant concerns about the practical applications of Zn–I 2 batteries. On the Zn metal anode side, uncontrollable zinc dendrite growth and side reactions will lead to poor cycling stability and eventually internal short-circuit. , On the other hand, insoluble I 2 in the cathode tends to combine with I – to form soluble polyiodide ions (I 3 – and I 5 – anions) into the electrolyte, leading to self-discharge and overcharge issues with unsatisfactory Coulombic efficiency. , More severely, the shuttle effect of intermediate polyiodide ions will react with anode materials, leading to the irreversible loss of cathode active materials and self-corrosion of Zn metal anodes, deteriorating the whole electrochemical performance of Zn–I 2 batteries dramatically. , Therefore, addressing these problems occurring in both the anode and cathode simultaneously is necessary for the development of high-performance Zn–I 2 batteries.…”