Colloid Electrolyte with Changed Li⁺ Solvation Structure for High-Power, Low-Temperature Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-ion batteries face challenges with low capacity and degradation during fast charging and low-temperature operation.
• Improving ion conductivity and interfacial stability is crucial for advanced battery performance.

Purpose of the Study:

• To design a colloid liquid electrolyte (CLE) that enhances lithium-ion battery performance under demanding conditions.
• To investigate the role of lithium thiocarbonate (LTC) colloids in improving interfacial kinetics and stability.

Main Methods:

• Development of a CLE by incorporating trace amounts of LTC colloids into a commercial carbonate electrolyte.
• Electrochemical characterization of the electrolyte and Li||CLE||NCA battery performance.
• Analysis of the cathode-electrolyte interface using techniques to study ion transfer and structural changes.

Main Results:

• The CLE significantly boosted Li+ conductivity (σLi+) to 15 mS cm-1 at 30°C and 4.5 mS cm-1 at -20°C.
• LTC colloids facilitated salt dissociation, accelerated Li+ desolvation, and formed an ultrathin, Li2CO3-rich cathode electrolyte interface.
• The Li||CLE||NCA battery achieved 135 mAh g-1 at 10C with 80% retention after 2000 cycles and demonstrated excellent low-temperature fast-charging capability.

Conclusions:

• The developed CLE effectively addresses the limitations of lithium-ion batteries in fast charging and low-temperature environments.
• The strategy of tailoring interfacial charge transfer using colloid additives is a promising approach for next-generation energy storage systems.