Electrolyte

Glassy Solid Electrolytes For Sodium-Ion Batteries

Electrolyte

Glassy Solid Electrolytes For Sodium-Ion Batteries

Soft superionic glasses demonstrate high conductivities and excellent formability In addition to high ionic conductivities, good formability of solid-state electrolytes is crucial for practical application, as the compressive step required to enable sufficient interfacial contact in a solid-state battery is a key manufacturing bottleneck due to the high pressures and temperatures often required. While amorphous glasses are an interesting subset of solid-state electrolytes due to their high deformability and absence of grain boundaries detrimental to ion diffusion, most glassy materials to date show restrictively low ion conductivities. Lin and Zhao et. al. report a new superionic oxychloride glass electrolyte, 0.5Na2O2-TaCl5 (NTOC), which demonstrates an ultrahigh ionic conductivity of 4.6 mS cm-1, more than 20 times higher than the previous record for glassy electrolytes. This impressive performance is attributed to unique local structures generated by the dual anion chemistry of chlorine and oxygen. Importantly, high structural formability is observed in NTOC, along with good chemical stability in dry air. When incorporated into an solid-state Na-ion battery, superior cycling stability over 500 cycles is observed, highlighting the potential of glassy NTOC electrolytes.

Dual anion chemistry in glassy electrolytes can drastically improve ionic conductivities. The 0.5Na2O2-TaCl5 composition shows promise as a practical Na-ion solid electrolyte due to its high conductivity, formability, and stability.

Academia | P. 227 Source: Lin, Zhao, Wang, Luo, Fu, Xiao, Gao, Li, Zhang, Xu, Yang, Hao, Duan, Sun, Guo, Huang, Sun

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