Quasi-Isolated Au Particles as Heterogeneous Seeds To Guide Uniform Zn Deposition for Aqueous Zinc-Ion Batteries

Abstract

As a promising anode for aqueous batteries, Zn metal shows a number of attractive advantages such as low cost, low redox potential, high capacity, and environmental benignity. Nevertheless, the quick growth of dendrites/protrusions on the “hostless” Zn anodes not only enlarges batteries’ internal resistance but also causes sudden shorting failure by piercing separators. Herein, we report a novel heterogeneous seed method to guide the morphology evolution of plated Zn. The heterogeneous seeds are sputtering-deposited quasi-isolated nano-Au particles (Au-NPs) that enable a uniform and stable Zn-plating/stripping process on the anodes. Tested on Zn|Zn symmetric cells, the Au-nanoparticle (NP) decorated Zn anodes (NA-Zn) demonstrate much better cycling stability than the bare ones (92 vs 2000 h). In NA-Zn|CNT/MnO2 batteries, this heterogeneous seed prolongs the lifetime of the device from ∼480 cycles up to 2000 cycles. This work offers a facile and promising Zn dendrite/protrusion suppressing route for the achievement of long-life Zn-ion batteries.

Challenges and Strategies for Constructing Highly Reversible Zinc Anodes in Aqueous Zinc‐Ion Batteries: Recent Progress and Future Perspectives

“…Metal coating strategy was developed by Zhi and co‐workers. [ 31 ] They decorated the zinc anode surface with Au nanoparticles (NPs) through a sputtering‐deposition method. The Au‐NPs on zinc surface worked as heterogeneous seeds for zinc nucleation during plating, guiding the uniform formation of zinc‐flake‐arrays on anodes.…”

Rechargeable Aqueous Zinc‐Ion Batteries with Mild Electrolytes: A Comprehensive Review

“…[171,172] The corrosion reactions between Zn metal and aqueous electrolyte (e. g., 3 M ZnSO 4 ) is not uniform, and the deepest corrosion pit reached upto 130 μm after a dwell time of 30 days. [173] Even though some novel intercalation-type anodes have been suggested (such as Na 0.14 TiS 2 [174] and Chevrel phase Zn 2 Mo 6 S 8 ), [112,175] the majority of ZIBs still use excess-mass Zn metal as anodes (in forms of foil [176,177] or powders) [11,21,22,178] for ample Zn 2 + supply. It is worth noting that Zn anodes with excess-mass (or shallow depth of discharge, DOD) will obviously depress the energy density of a fully packaged ZIBs, due to the heavy anode design with inefficient Zn utilization.…”

“…By making good use of Zn anodes' dendrite forming nature with pre-deposited Au nano-particles (as heterogeneous Zn nuclei), the plane surface of Zn foils could be in situ transformed into uniform array of Zn micro-flakes during cycling (Figure 12b-d), resulting in a profoundly improved cycling stability for both anode and full batteries. [176] Introducing heterogeneous nuclei (such as Sn nano-particles) onto current collectors is also helpful for the achievement of high performance Zn anodes. [193] In situ electro-healing strategy for in-service Zn anodes: The formation of Zn dendrites are severely dependent on the charge/discharge conditions of the ZIBs.…”

A Quasi-gel SiO2/Sodium Alginate (SA) Composite Electrolyte for Long-life Zinc-manganese Aqueous Batteries

“…采用共沉淀法制备 MnO 2 /CNT 复合正极材料 [14] : 的-Si-O-Si-(1109 cm -1 )、-Si-OH(969 cm -1 )、 -Si-O(798 和 472 cm -1 )、和-OH(1631 cm -1 )特征吸 收峰 [7,23] 。在 SA 电解质的光谱中观测到 SA 分子的 -COO -(1625 和 1418 cm -1 )和-C-O(1029 cm -1 )吸收 峰 [24][25][26] [32][33] 。在加入添加剂后, 电池的第二个放电平 台电压稍低, 这可能是由于添加剂引起电解质粘度 增大, 进而影响了 Zn 2+ 的迁移速率所造成的 [34] [35][36] 。 在图 7(a)的 Zn-MnO 2 电池电化学阻抗图谱中, 高频区的半圆弧反映了电池的电荷转移电阻。由图 可知, 使用 SA/SiO 2 准凝胶电解质的电池电荷转移 电阻最小(半圆弧最小), 说明该电池的电化学反应 动力学过程顺畅 [37] 。这一结果应该与均匀的锌沉积 行为有关 [14,17] (见图 3(f)、图 5(f)和图 S6)。根据 Sun [14][15] 或多孔纤维层 [7,39] 的作用, 可以引导 Zn 2+ 更加均匀地迁移, 避免 Zn 2+ 向尖端处快速集中从而 降低锌沉积过程中 Zn 2+ 的浓差极化, 避免锌枝晶快 速生长。与此同时, SA/SiO 2 准凝胶电解质较强的电 子绝缘性可以将锌沉积反应限域在锌负极表面, 实 现自下而上的锌沉积过程 [11,14] 。此外, 准凝胶电解 质中的 SiO 2 具有较高的模量, 也有利于限制锌枝 晶生长 [40]…”

“…Key words: zinc-manganese battery; zinc dendrite; quasi-gel electrolyte; sodium alginate; silica 可充电锌锰(Zn-MnO 2 )电池具有高安全性、 高环 保性、高性价比的三重优点, 不仅适合用作大规模 储能电池 [1][2] , 在混合动力汽车和电动自行车等领 域也具有潜在的应用价值 [3][4][5] 。然而, 受"尖端效应" 影响, 金属锌负极表面因粗糙度出现的微观凸起在 充电过程中会产生较强的局部电场, 通过吸引锌离 子沉积快速生长成大尺寸锌枝晶 [6][7] 。锌枝晶生长 增加了负极表面的粗糙度, 进一步强化了"尖端效 应", 从而形成恶性循环。负极表面生成疏松锌枝 晶不仅会引起电池内阻增大、 容量衰减, 而且会刺 穿隔膜, 引起电池短路等一系列问题 [8] 。枝晶生长 是金属负极电池普遍存在的问题, 不仅制约着锌 电池 [9][10] , 也同样困扰着锂、钠、钾等金属电池的 发展 [11][12][13] 。 为了提升锌电池的性能, 研究人员近年来设计 开发了多种抑制锌枝晶的方法, 主要机理有: 1) 保 证电解液向负极迁移的均匀性, 降低负极表面 Zn 2+ 的浓差极化 [14][15] ; 2) 增加负极表面锌成核位点, 通 过提高锌晶核的密度与分布均匀性保证锌均匀沉 积 [16][17] ; 3) 增大负极集流体的比表面积, 降低集流 体表面上的电流密度并减少锌沉积量 [9][10] ; 4) 限制 金属锌在负极上的沉积位置, 避免锌枝晶刺穿隔 膜 [8] 。 这些方法都具有很好的锌枝晶抑制效果, 但制 备或处理过程复杂。例如, 在制备泡沫锌负极时 [9] , 需要首先将锌粉注塑成型, 然后高温烧结/氧化, 最 后通过电化学还原方可获得最终样品, 实验过程非 常繁杂。 不同于负极或负极集流体改性过程, 通过添加 剂改性电解质来调控锌沉积过程是一种更简单易行 的金属枝晶抑制方法 [18][19] 。由于金属锌的平衡电位 较高, 反应活性较低, 因此锌电池电解质添加剂的 选择比碱金属电池更加灵活。 最近, Xu 等 [20] 、 Huang 等 [21] 研究发现, 在水系电解质体系中添加乙醚和二 氧化硅/乙氧基脂肪甲酯可以有效抑制锌枝晶生长, 延长电池使用寿命。此外, 有些添加剂还可以将电 解质转变成准凝胶状态, 有效解决电池破损后的电 解质泄漏问题 [22]…”