Promising Pre-Lithiation Agent Li₂C₂O₄@KB for High-Performance NCM622 Cell

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Active lithium loss during solid electrolyte interphase (SEI) formation in lithium-ion batteries (LIBs) limits coulombic efficiency and energy density.
• Conventional pre-lithiation agents often suffer from complex synthesis and air instability.
• Cathode pre-lithiation is a key strategy to mitigate irreversible lithium consumption.

Purpose of the Study:

• To develop a stable and efficient cathode pre-lithiation agent to overcome the limitations of existing methods.
• To synthesize a Ketjen black-coated lithium oxalate nanocomposite (Li₂C₂O₄@KB) for improved lithium-ion battery performance.
• To evaluate the electrochemical performance of the Li₂C₂O₄@KB composite as a pre-lithiation additive in NCM622 full cells.

Main Methods:

• High-energy ball milling and spray drying were employed for the synthesis of the Li₂C₂O₄@KB nanocomposite.
• The composite was characterized for its structural and electrochemical properties.
• NCM622 full cells were assembled using the Li₂C₂O₄@KB composite as a cathode pre-lithiation additive.

Main Results:

• The Li₂C₂O₄@KB composite exhibits a mild decomposition potential (4.26 V vs. Li⁺/Li) and high theoretical lithium compensation capacity (525 mAh·g^-1).
• Incorporation of Li₂C₂O₄@KB in NCM622 full cells resulted in an 18.21 mAh·g^-1 increase in initial capacity at 0.3 C and a 29.22% improvement in capacity retention after 50 cycles.
• At 1 C, the initial capacity increased by 15.79 mAh·g^-1 with a 7.72% enhancement in retention after 100 cycles.

Conclusions:

• The developed Li₂C₂O₄@KB nanocomposite offers a practical and effective solution for cathode pre-lithiation in lithium-ion batteries.
• This material significantly enhances the initial capacity and long-term cycling stability of LIBs.
• The Li₂C₂O₄@KB composite shows great promise for advancing high-energy-density lithium-ion battery technologies.