Ta-based amorphous chloride solid electrolytes: A review

All-solid-state lithium batteries (ASSLBs) have attracted significant attention due to their superior safety and higher energy density compared to traditional liquid lithium-ion batteries. Among various solid electrolytes, Ta-based amorphous chloride solid electrolytes (Ta-ACSEs) have emerged as critical materials owing to their high ionic conductivity (>10 mS cm −1 at room temperature), exceptional electrochemical stability (up to 4V to 6 V vs. Li + /Li), ultralow activation energy of 0.165 eV and interfacial compatibility with high-voltage cathode materials. This review systematically summarizes recent breakthroughs in Ta-ACSEs, aiming to provide a deeper understanding of progress in the field and to accelerate their practical implementation. First, we delve into the fundamental ion transport mechanisms governing Ta-ACSEs. Subsequently, we categorize these electrolytes based on the characteristic scale of their dynamic reorganization behavior. Following this, we critically assess the decisive role of key synthesis parameters and dissect associated interfacial stability challenges. Finally, we discuss the main challenges confronting Ta-ACSEs and propose future research directions aimed at advancing their practical deployment in ASSLBs.