Regulate the Solvation Structure and Interface by Nitrate in Phosphate-Based Electrolytes for 4.5 V-Class Ni-Rich...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Phosphate-based electrolytes offer high safety but suffer from poor electrochemical stability, limiting their use with lithium metal anodes and Ni-rich cathodes.
• Advanced lithium metal batteries (LMBs) require electrolytes with improved stability for high-energy-density applications.

Purpose of the Study:

• To develop a phosphate-based electrolyte with enhanced electrochemical stability for compatibility with advanced battery components.
• To improve the performance and safety of lithium metal batteries using a novel electrolyte design.

Main Methods:

• Development of a phosphate-based localized high-concentration electrolyte featuring a nitrate-driven solvation structure.
• Investigation of the nitrate-derived N-rich inorganic interface for stabilizing cathode and anode interfaces.
• Electrochemical testing of Li||NCM811 cells to evaluate cycle stability and capacity retention at various voltages.

Main Results:

• The novel electrolyte effectively stabilizes the LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathode interface and improves lithium deposition morphology on the anode.
• Li||NCM811 cells demonstrated exceptional long-cycle stability, retaining >80% capacity after 800 cycles at 4.3 V.
• A capacity retention of 93.3% after 200 cycles was achieved at a high voltage of 4.5 V.

Conclusions:

• The developed phosphate-based electrolyte with a nitrate-driven solvation structure enhances the electrochemical stability of Ni-rich LMBs.
• This work expands the construction of anion-rich solvation structures, paving the way for safer, high-performance lithium metal batteries.