# Insights into Aquatic Safety and Environmental Risks of Doped LLZO Solid-State Electrolytes

## TL;DR

This study examines the environmental safety of doped LLZO solid-state electrolytes, finding they may be less harmful than traditional battery materials.

## Contribution

The novelty lies in assessing aquatic toxicity and environmental risks of doped LLZO solid-state electrolytes using zebrafish embryos.

## Key findings

- Lithium and aluminum release from LLZO was detected but did not cause acute toxicity in zebrafish embryos.
- Doped LLZO shows potential as a safer alternative to organic electrolytes in batteries.
- Further research is needed on chronic exposure and ecological impacts of LLZO.

## Abstract

Solid-state batteries
are considered the next advancement in lithium-ion
battery technology, offering enhanced energy density and safety. However,
the toxicity and environmental risks associated with the production
and disposal of these materials remain insufficiently explored. This
study investigates the aquatic toxicity and environmental concerns
of Al- and Ta-doped garnet Li7La3Zr2O12 (LLZO), a promising solid-state electrolyte. Comprehensive
material characterization was performed to evaluate the interactions
of milled LLZO with aqueous environments, and potential toxicological
effects of LLZO were assessed through an acute fish embryotoxicity
(FET) assay using zebrafish embryos. Lithium and aluminum release
were detected; however, these alterations were insufficient to induce
acute toxicological effects in zebrafish embryos, even in the absence
of the chorion barrier. Despite these findings suggesting the potential
of doped LLZO as a less harmful alternative to conventional organic
electrolytes, further studies addressing chronic exposure, species-specific
responses, and broader ecological impacts are essential before LLZO
can be considered environmentally safe.