A Sacrificial Additive Strategy: Integrates Scavenging and Byproduct Utilization for High-Voltage Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-ion batteries are crucial for portable electronics but require higher energy density for advanced applications.
• Current sacrificial additives improve battery voltage but their by-products' potential is largely unexplored.
• There is a need for novel electrolyte strategies to enhance lithium-ion battery performance and longevity.

Purpose of the Study:

• To investigate trimethylsilyl trifluoromethanesulfonate (TMSOTF) as a multifunctional additive in lithium-ion batteries.
• To explore the utilization of TMSOTF by-products for forming a protective interphase.
• To enhance the operating voltage and cycle stability of LiCoO2||Li cells.

Main Methods:

• Incorporation of 1 wt% TMSOTF into the electrolyte of LiCoO2||Li cells.
• Electrochemical testing, including cycling at high voltage (3.0-4.65 V).
• Analysis of interphase formation and additive functionality.

Main Results:

• TMSOTF acts as a multifunctional additive, scavenging detrimental species and directing by-product formation.
• The additive facilitates the creation of a protective interphase layer on battery components.
• LiCoO2||Li cells with 1 wt% TMSOTF retained 79.82% capacity after 200 cycles, outperforming conventional electrolytes.

Conclusions:

• TMSOTF is an effective additive for improving the high-voltage performance and cycle life of lithium-ion batteries.
• This study introduces a novel paradigm of byproduct-utilization for designing advanced sacrificial additives.
• The findings pave the way for next-generation high-energy-density lithium-ion battery electrolytes.