Molecular deciphering of hydrophobic, Zinc-philic and robust Amino-functionalized Polysilane for Dendrite-free Zn Anode
Energy Storage Materials
As one of most prospective anode materials of aqueous batteries, Zn metal faces severe electrolyte corrosion and fatal dendrite growth. To address these issues, the electrolyte/Zn interface needs to be carefully engineered. Here, a dense and robust layer of polysilane functionalized by -NH2 is coated on Zn in a new way. In this layer, -NH2 provides adequate alkalinity and important interaction with Zn2+, enhancing the hydrolysis and regulating the Zn2+ flux. Propyl groups increase the flexibility to buffer inevitable strain/stress and the hydrophobicity to reduce the permeation of water. Si-O-Zn enables the durable interface between Zn and this layer. These results lead to superior mechanical property, suppressed side reactions and uniform plating/stripping. Hence, it shows excellent electrochemical performance, ∼300 hours at 20 mA cm-2 for 10 mAh cm-2 (Depth of Discharge ∼57%) in symmetrical cells, and average Coulombic efficiency of 99.8% during 800 cycles for 3 mAh cm-2 in asymmetrical cells. Even at a high loading of MnO2, a small N/P ratio and a limited electrolyte, the full cells coupled still display a capacity of ∼2.93 mAh cm-2 after 100 cycles at 0.5 C.
Open Access Status
This publication is not available as open access