Sacrificial Prelithiation Using Different Lithium Salt-Coated LNMO Cathodes for Stabilizing the Electrode Structure...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Cobalt-free, high-voltage spinel cathode LiNi0.5Mn1.5O4 (LNMO) offers high energy/power densities for next-generation lithium-ion batteries (LIBs).
• High operating voltage (4.7 V) causes electrolyte decomposition and structural damage.
• Irreversible lithium loss in early cycles reduces capacity, hindering commercialization.

Purpose of the Study:

• To investigate the use of sacrificial salts for prelithiation of LNMO electrodes.
• To evaluate the influence of different sacrificial salts (Li2C2O4, Li2CO3, CH3COOLi) on LIB performance.
• To leverage LNMO's catalytic effect and sacrificial salt prelithiation for improved battery stability and capacity.

Main Methods:

• Blending sacrificial salts with LNMO to create prelithiated electrodes (LNMO-Sac).
• Catalytic decomposition of sacrificial salts by LNMO.
• Formation of a stable electrode-electrolyte interface.
• Electrochemical performance testing of LIBs with prelithiated electrodes.

Main Results:

• LNMO effectively catalyzes sacrificial salt decomposition, forming a stable interface and mitigating electrode damage.
• Li2C2O4 supplementation significantly improved active lithium levels and electrochemical performance.
• LNMO-Li2C2O4 achieved 137.9 mAh g-1 at 1C with 85.9% capacity retention after 500 cycles.
• LNMO-LO/Gr full cell showed initial capacity of 117.9 mAh g-1, retaining 79.4 mAh g-1 after 300 cycles.

Conclusions:

• Sacrificial salt prelithiation is a feasible strategy for lithium replenishment in LNMO cathodes.
• Li2C2O4 is a highly effective sacrificial salt for enhancing LNMO-based LIB performance.
• This approach mitigates electrolyte decomposition and improves long-term cycling stability for practical LIB applications.