Design And Performance Study Of Electrolyte Additive Based On Aqueous Zinc Ion Battery

Global environmental degradation,energy shortage and demand for upgrading electrode-chemical storage facilities with high capacity,low cost,and high security pushed the development of water-based batteries,especially one water-based zinc ion（AZIBs）,and the AZIBs is tended to be a highly commercialized substitute for lithium-ion batteries.Although AZIBs enjoys advantages and prospects on energy storage in the future,there are still many defects,such as the occurrence of zinc dendrites,zinc corrosion,and side reactions such as hydrogen evolution,which lead to poor cycling stability and low Coulomb efficiency（CE）of batteries.The occurrence of zinc dendrite is the most prime reason,and it easily penetrates the battery separator and causes short circuit.The large surface capacity and high current density would make the occurrence of zinc dendrite particularly serious.To solve the problem of zinc dendrite in zinc anode,various strategies have been adopted,such as zinc anode modification,electrolyte design and separator improvement.Among them,designing new electrolytes with the usage of additives is considered to be one of promising methods for its efficiency and cost.In this paper,the author firstly reviewed the research on dendrite suppression of zinc anode in recent years,and then proposed two electrolyte additives improving the traditional electrolyte to enhance the performance of zinc ion batteries.The research proposals are as follows:（1）Glucosamine hydrochloride（GH）is used as electrolyte additive,which shows that the symmetrical battery Zn//Zn assembled with zinc sulfate electrolyte with 0.4 g L^-1 GH additive can stably cycle for more than 900 h under the condition of 1 m A cm^-2current density and 0.5m Ah cm^-2 area capacity,and stably cycles for more than 260 h under the condition of 5 m A cm^-2symmetrical battery and 2.5 m Ah cm^-2area capacity.Moreover,zinc anode performs better on electrode-chemistry in the GH additive electrolyte system.The characterization test directly shows the effect of GH additive on zinc anode,which makes the deposition of zinc ions more compact and uniform.The discharge capacity of full battery Zn//MnO₂ assembled with GH additive electrolyte reaches 295.54 m Ah g^-1 at the current density of 1 C,wth higher capacity retention after 400 cycles,as well as stabler the coulomb efficiency.This proves that GH additive can be potentially used in electrolyte additive.（2）Gluconic acid sodium salt（GAS）is used as an additive for Zn SO₄ electrolyte of zinc ion battery.The results show that adding 0.1 M GAS can greatly improve the cycling of symmetrical battery Zn//Zn,and the stable cycling time is more than 2480 h under the conditions of 1.0 m A cm^-2 and 0.5 m Ah cm^-2.Electrode-chemical and characterization tests shows that GAS additives performs a stabilizing effect on the deposition of zinc ions on zinc anodes with an inhibitory effect on the production of by-products,and can slow down the rate of zinc corrosion.This proves that GAS can be potentially used as an electrolyte additive for AZIBs.