Optimizing Amphoteric Cellulose Additives with Complexation-Adsorption Mechanisms to Stabilize the Zn Anode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc batteries (AZBs) face challenges from zinc dendrite growth and side reactions, hindering commercial use.
• Amphoteric electrolyte additives are promising for stabilizing the zinc anode, but their mechanisms require deeper understanding.
• The impact of charge composition in amphoteric additives on zinc electroplating is often overlooked.

Purpose of the Study:

• To investigate the complex interplay between complexation and adsorption mechanisms of amphoteric cellulose additives in AZBs.
• To elucidate how the charge composition of amphoteric additives influences zinc ion (Zn2+) electroplating behavior.
• To demonstrate a strategy for designing effective electrolyte additives for stable AZBs.

Main Methods:

• Utilized amphoteric cellulose as a model additive with controllable positive/negative group ratios.
• Investigated the complexation and adsorption mechanisms of the additive on the zinc anode.
• Evaluated the performance of AZBs with the optimized additive in Zn||Zn and Zn||NH4V4O10 cells.

Main Results:

• Amphoteric cellulose guides Zn2+ deposition and forms a uniform protective layer on the zinc surface.
• The optimized additive effectively suppresses dendrite growth and side reactions in AZBs.
• Achieved a high depth of discharge of 68.4% in Zn||Zn cells and 310 mAh g-1 in Zn||NH4V4O10 cells.

Conclusions:

• The charge composition of amphoteric electrolyte additives plays a critical role in AZB performance.
• Amphoteric cellulose offers a viable strategy for developing dendrite-free and stable AZBs.
• This work provides insights into additive design for advancing the commercialization of AZBs.