Static and Dynamic Studies on LiNi1/3 Co1/3 Mn1/3 O2 -Based Suspensions for Semi-Solid Flow Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Semi-solid flow batteries (SSFB) offer potential for grid-scale energy storage.
• LiNi1/3 Co1/3 Mn1/3 O2 (LNCM) is a promising cathode material for SSFBs.
• The rheological properties and electrochemical performance of SSFB suspensions are critical for efficient operation.

Purpose of the Study:

• To investigate the effect of electroconductive carbon black (KetjenBlack, KB) content on the electrochemical performance and rheological properties of LNCM-based SSFB suspensions.
• To analyze the impedance characteristics of SSFB half-cells under varying KB concentrations.
• To understand the relationship between suspension properties, cell resistance, and overall battery performance.

Main Methods:

• Galvanostatic charge/discharge cycling of LNCM-based half-cells.
• Electrochemical impedance spectroscopy (EIS) to analyze cell resistance.
• Rheological property measurements of the suspensions.
• Variations in KetjenBlack (KB) content in the LNCM suspensions.

Main Results:

• Suspension performance, including capacity and coulombic efficiency, is significantly influenced by KB content.
• Static conditions: High capacity (130 mAh/g) and 90% coulombic efficiency achieved with specific KB and LNCM volume percentages.
• Impedance analysis revealed that contact resistance, modeled by a resistor and constant phase element (CPE), dominates half-cell impedance.
• Flow conditions: Cell potential is dependent on current density, with measurable overpotentials at different current rates.

Conclusions:

• Optimizing KetjenBlack content is crucial for enhancing the electrochemical performance of LNCM-based SSFB suspensions.
• Contact resistance plays a significant role in the overall electrochemical performance of these systems.
• The findings provide valuable insights for designing and fabricating high-performance SSFBs.