Rational Design of a Composite Electrode to Realize a High-Performance All-Solid-State Battery

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• All-solid-state batteries (ASBs) offer enhanced safety and energy density.
• Lithium superionic conductor Li10GeP2S12 (LGPS) exhibits high ionic conductivity but faces limitations in composite electrodes due to porosity.
• Optimizing electrode structure and interfaces is critical for practical ASB implementation.

Purpose of the Study:

• To enhance the performance of LGPS-based composite electrodes in ASBs.
• To investigate the effect of ionic liquid pore filling on electrode structure and Li+ conductivity.
• To improve the interfacial contact between active materials and LGPS particles.

Main Methods:

• Coating LGPS powder with N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Py14][TFSI]) ionic liquid via a wet process.
• Fabricating sheet-type composite electrodes using a conventional casting procedure.
• Evaluating the electrochemical performance, including reversible capacity and power characteristics, of the modified electrodes.

Main Results:

• The [Py14][TFSI]-embedded composite electrode demonstrated significantly improved reversible capacity.
• Enhanced power characteristics were observed in the ionic liquid-modified electrodes.
• Pore-filling effectively increased interfacial contact areas between active materials and LGPS particles.

Conclusions:

• Ionic liquid pore-filling with [Py14][TFSI] is an effective strategy to improve LGPS-based composite electrode reliability.
• This method enhances Li+ transport pathways within the composite electrode, leading to superior electrochemical performance.
• The study highlights the potential of tailored pore structures for advancing ASB technology.