Inorganic Battery Materials

Chemistry of Soft Matter Battery Electrolytes

Jelena Popovic

Max Planck Institute for Solid State Research, Stuttgart, Germany

1. 1 Introduction
2. 2 Ionic Conductivities and Lithium (Sodium) Transference Numbers
3. 3 Soft Matter Lithium and Sodium Electrolytes
4. 4 Stability of the Electrolyte/Electrode Interfaces
5. 5 Specific Electrolyte Issues in L–S and L–O₂ Batteries
6. 6 Electrolytes for Multivalent Batteries
7. 7 Conclusions and Outlook
8. 8 Abbreviations and Acronyms
9. 9 References

1 Introduction

Electrolytes are key components of lithium and sodium ion batteries, enabling ion transport in broad electrochemical windows, and finally determining cell's power density as well as long‐term performance and stability. Soft matter electrolytes have been used since the very early stages of battery development due to the beneficial properties such as high room temperature ionic conductivities, good wettability of the nanostructured electrodes, flexibility, and stable solid electrolyte interphase (SEI). Unlike their inorganic competitors, soft matter electrolytes rarely suffer from large volume changes upon electrochemical cycling or great charge‐transfer resistances at electrode/electrolyte interfaces. The major issues, on the other hand, lie in the noncompatibility with high power electrodes and large concentration gradients due to low lithium (sodium) transference numbers (t_Li(Na) < 0.5), dendrite formation in contact with metal electrodes as a consequence of moderately electronically conductive or ...