Rheological Properties of Aqueous Sodium Alginate Slurries for LTO Battery Electrodes.

Christina Toigo,Catia Arbizzani,Milan Kracalik,Karl-Heinz Pettinger,Elke Bradt

doi:10.3390/polym13203582

Abstract

Rheological properties of electrode slurries have been intensively studied for manifold different combinations of active materials and binders. Standardly, solvent-based systems are under use, but a trend towards water-based electrode manufacturing is becoming more and more important. The different solvent is beneficial in terms of sustainability and process safety but is also accompanied by some disadvantages such as extraction of residual humidity and a higher complexity concerning slurry stability. Li4Ti5O12 (LTO) active material provides good long-term stability and can be processed in aqueous solutions. Combining the LTO active material with sodium alginate (SA) as a promising biobased polymer binder reveals good electrochemical properties but suffers from bad slurry stability. In this work, we present a comprehensive rheological study on material interactions in anode slurries consisting of LTO and SA, based on a complex interaction of differentially sized materials. The use of two different surfactants—namely, an anionic and non-ionic one, to enhance slurry stability, compared with surfactant-free slurry.

Highlights

Intensive research on the optimisation of lithium-ion batteries (LIBs) is currently underway due to the ongoing decarbonisation of the economy and rising demand for energy storage systems
Both surfactants were taken from a pre-prepared solution of 10% dissolved in deionised water and diluted further in deionised water to reach a total concentration of 0.5%
This is a known effect for water-based battery slurries [21]

Summary

Introduction

Intensive research on the optimisation of lithium-ion batteries (LIBs) is currently underway due to the ongoing decarbonisation of the economy and rising demand for energy storage systems. The commercially used active materials on the anodic side of LIBs are limited to a rather small number—namely, graphite, lithium titanium oxide, or silicon-based materials [1]. All of these active materials have their pros and cons; for example, graphite, as the most used material, exhibits the formation of an unstable solid electrolyte interphase (SEI). Silicon is a further possible anode material with a high gravimetric capacity of 3600 mAh g−1 and several advantages such as low toxicity and high natural abundance [3] It suffers from both low conductivity and low initial Coulombic efficiency [4].

Methods

Results

Conclusion