Competitive Adsorption and Structural Reinforcement Synergy Stabilizes High-Voltage Quasi-Solid-State Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Quasi-solid-state batteries (QSSBs) offer high energy density and safety.
• However, unstable interfaces and cathode degradation limit their performance, especially with high-voltage cathodes.

Purpose of the Study:

• To develop a strategy for stabilizing the cathode/electrolyte interface and reinforcing cathode structure in high-voltage QSSBs.
• To address challenges of interface instability and material degradation.

Main Methods:

• Incorporation of a Cu-centered self-adsorption molecule into the polymer electrolyte.
• Utilizing competitive adsorption to form a protective interphase layer.
• Employing dynamic Cu doping to reinforce cathode structure during cycling.

Main Results:

• Formation of a uniform, F-rich cathode/electrolyte interphase with enhanced stability.
• Suppression of cathode degradation and improved structural integrity.
• Demonstrated long cycle life with 80% capacity retention after 400 cycles at 4.6 V in coin cells and over 1000 cycles at 4.5 V.

Conclusions:

• The competitive adsorption and structural reinforcement synergy (CASR) strategy effectively stabilizes high-voltage QSSBs.
• This approach shows significant promise for advancing next-generation battery technologies.
• Successful demonstration in a 1 Ah-level pouch cell validates the strategy's practical potential.