Constructing a Protective Interface Film on Layered Lithium-Rich Cathode Using an Electrolyte Additive with Special...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Layered lithium-rich cathodes are crucial for high-energy-density batteries.
• Developing stable electrolytes is key to improving battery cycle life and performance.
• Existing electrolyte additives often face limitations in forming robust protective layers.

Purpose of the Study:

• To investigate Phenyl vinyl sulfone (PVS) as a novel electrolyte additive for layered lithium-rich cathodes.
• To evaluate the impact of PVS on the electrochemical performance and interface stability.
• To understand the structure-property relationships of PVS in enhancing cathode protection.

Main Methods:

• Electrochemical testing including charge-discharge cycling of Li(Li_0.2Mn_0.54Ni_0.13Co_0.13)O₂ cathodes.
• Addition of 1 wt% PVS to a standard electrolyte (1.0 M LiPF₆ in EC/EMC/DEC).
• Electrochemical measurements, theoretical calculations, and physical characterizations to analyze the interface film.

Main Results:

• PVS addition significantly improves capacity retention of the cathode to approximately 80% after 240 cycles at 0.5 C.
• A protective interface film is successfully constructed on the cathode surface.
• The unique molecular structure of PVS (double bond, aromatic ring, sulfur) contributes to film stability and ionic conductivity.

Conclusions:

• Phenyl vinyl sulfone is an effective electrolyte additive for stabilizing layered lithium-rich cathodes.
• PVS promotes the formation of a stable and ionically conductive interface film, enhancing battery cycle life.
• The molecular design of PVS offers a promising strategy for developing advanced battery electrolytes.