Three-dimensional cross-linked interface with high ionic transference number and electrical conductivity for high-performance aqueous Zn-ion batteries

• Published in: Solid state ionics Vol. 421; p. 116790
• Main Authors: Luo, Hao, Li, Chengze, Sheng, Wenxiang, Yuan, Weimin, Chen, Xiao, Ma, Qianqian, Li, Xiaowu, Sun, Zhenjie, Li, Peng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2025
• Subjects: Anode modification; Aqueous zinc ion battery; Ionic transference number; PPy/MCC layer; Zinc dendrite; PPy/MCC layer; Ionic transference number; Anode modification; Zinc dendrite; Aqueous zinc ion battery
• ISSN: 0167-2738
• DOI: 10.1016/j.ssi.2025.116790

Aqueous zinc-ion batteries (AZIBs) have been the subject of considerable research due to their safety and energy density, but these processes are constrained by the growth of dendrites and interfacial side reactions. Herein, a three-dimensional cross-linked polypyrrole and microcrystalline cellulose (PPy/MCC) composites are fabricated through the force of hydrogen bonding on the surface of zinc anodes. The distinctive cross-linking conductive network could enhance the Zn2+ transport process and storage, ensuring uniform charge distribution and further elevating the Zn2+ transference number. The abundant functional groups of PPy/MCC offer numerous zincophilic nucleation sites thereby promoting uniform zinc deposition. Additionally, the hydrophobic PPy/MCC coating acts as a barrier, shielding the zinc anode from the aqueous electrolyte and effectively inhibiting side reactions like corrosion and hydrogen production. Consequently, the zinc anode coated with the PPy/MCC layer (PPy/MCC@Zn) achieves steady and reversible Zn cycling. The PPy/MCC@Zn//PPy/MCC@Zn symmetric batteries harvest a long cycling stability exceeding 3400 h at a current density of 1 mA cm−2, 1 mAh cm−2. The PPy/MCC@Zn//Cu battery achieves a remarkable average Coulombic efficiency (CE) of 99.48 % at 2 mA cm−2, 2 mAh cm−2. The practical full battery, coupled with the I2- activated carbon (AC) cathode, also demonstrates stable performance over 4000 cycles. Cross-linked polypyrrole and microcrystalline cellulose (PPy/MCC) composites with high ionic transfer number and electronic conductivity were prepared and coated on the zinc anode surface as a protective layer. The special structure of PPy/MCC layer with a quantity of nucleation sites can impede the formation of dendrites and promotes Zn ion transport which enables a dendrite-free Zn anode. [Display omitted] •We constructed multifunctional layers of polypyrrole and microcrystalline cellulose (PPy/MCC) composites on the surface of zinc negative electrodes.•The abundant functional groups and uninterrupted conductive network of PPy/MCC provide a quantity of nucleation sites to accelerate Zn2+ transport.•The symmetric batteries survive up to 3400 h at 1 mA cm-2 and full batteries could cycle stably for over 4000 cycles.