A Designed Durable Electrolyte for High-Voltage Lithium-Ion Batteries and Mechanism Analysis

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Rechargeable lithium-ion batteries (LIBs) are crucial for electronics and electric vehicles.
• Increasing energy density is limited by electrode capacity and electrolyte decomposition at high voltages (>4.4 V).
• Aggravated electrolyte decomposition leads to capacity fading and battery failure.

Purpose of the Study:

• To develop a durable electrolyte for high-voltage LIBs.
• To suppress electrolyte decomposition at elevated cut-off voltages.
• To improve cycling stability, rate capability, and high-temperature performance.

Main Methods:

• Formulated a novel electrolyte using mixed linear alkyl carbonates and cyclic carbonate additives.
• Excluded ethylene carbonate (EC) to minimize electrolyte decomposition.
• Tested the electrolyte in a graphite|LiNi0.6Co0.2Mn0.2O2 (NCM622) battery at 4.45 V.

Main Results:

• Achieved extremely high cycling stability and rate capability.
• Demonstrated excellent high-temperature storage performance.
• Observed good compatibility with graphite anode and mitigated NCM622 cathode degradation.

Conclusions:

• The new electrolyte enables stable operation of LIBs at high voltages (>4.4 V).
• The formulation avoids ethylene carbonate, suppressing decomposition.
• This work offers a promising path for high-energy LIBs and electrode/electrolyte interface studies.