Polymorphism control of fast-sintered NASICON-type LiZr2(PO4)3

Long processing times and high temperature sintering can lead to high energy intensities and costs for all solid state battery manufacturing. Fast-sintering methods that are compatible with air can potentially overcome these challenges. Dynamic pulses of electrified heat also provide a pathway for manipulating materials and material transformation pathways to provide more control over structural heterogeneity. Herein, we examine how ultra-fast sintering approaches impact polymorphism in NASICON-type solid electrolytes (e.g. LiZr2(PO4)3). The role of microstructure (e.g. porosity), the polymorphism in starting powders, and the presence of liquid sintering aids are all examined to understand how polymorphic phases can be tailored with fast-sintering approaches. Fast sintering techniques which decrease the loss of volatile lithium may enable high density solid electrolytes with tailored material phases.