Study On Electrochemical Performance Of Zinc Electrode Fabricated By Electrodeposition On Foam Silver Collector

Zinc-silver battery had already applied widely in many fields such asaerospace, military because of its excellent security, stable discharge voltageand high specific power. In recent years, a new generation of zinc-silverbattery with high current discharge capacity and energy density was paidattention widely because of the rapid development of electrical appliances.One of effective ways to improve the overall performance of zinc-silverbattery was to form a new zinc electrode structure, instead of traditionalcompressed or pasted zinc electrode with complex preparation process andlimited high-current discharge capacity. In this paper, based onthree-dimensional porous structure of the foam silver matrix prepared byelectrochemical deposition, the morphology and structure of zinc electrodewas fabricated by electrochemical deposition was studied. Through some keyparameters optimization, both the morphology and structure of zinc electrodewas adjusted, while the discharge specific capacity increased doubled.The apparent influences of electrodeposition process on both zinc-anodemorphology and discharge performance were studied, on which the currentdensity had the greatest impact. As the current density increased, the zincmorphology varied greatly from granular, branched to rod. When the currentdensity was100mAh g^-1, the discharge specific capacity was best and up to595mAh g^-1with good dendritic morphology and large specific surface area.the discharge specific capacity would decreased as the temperature raisedfrom room temperature to80℃. KOH concentration played a role on bothzinc morphology and zinc deposition potential. The discharge specificcapacity came up to573.66mAh g^-1when the KOH density was1.20g cm-2.Ultrasonic was another key factor to improve zinc-morphology anddischarge performance. Ultrasonic was beneficial of generating smaller zincdendrite, increasing contact area and improving large current dischargecapability. The specific discharge property was best and reached686.92mAh g^-1（3C） with the Ultrasonic of31kHz. The influences of additive onelectrodeposited zinc discharge performance were obvious. When2.0g L-1EDTA was added, the discharge specific capacity reached765.60mAh g^-1with smaller zinc dendrite. When additional EDTA continued to add, thedischarge performance decreased because of steric effects and repression on dendrites anisotropy. The addition of PVP accelerated the speed of crystalgrowth and zinc dendrite thickness increased.The characteristic of battery activation was investigated in this paper. Itshowed that discharge specific capacity was only391.97mAh g^-1when therest time is1min, and un-fully activated. The discharge specific capacityreached600mAh g^-1or above with stable when the rest time was or morethan5min. The various discharge rate performance of zinc electrode was alsostudied. In this paper. The discharge specific capacity of zinc electrode wasup to734.16mAh g^-1（1C）, or363.27mAh g^-1（10C）. Moreover, the influencesof different pored polyurethane on zinc anode electrochemical performancewere analyzed. The specific discharge of zinc electrode fabricated byelectrodeposition with450um560um680um polyurethane foam matrix were497.41mAh g^-1587.40mAh g^-1705.26mAh g^-1, respectively（3C）, whichwere much higher than that of factory electrode. Moreover, when3000um-pored polyurethane was applied, the specific discharge property wasamazingly up to785.44mAh g^-1（3C） or565.75mAh g （10C）.