In a solid-state battery, a solid electrolyte component replaces the liquid electrolyte,
improving the safety and the amount of energy that the battery can store. However,
using a solid-state electrolyte brings other challenges, such as resistance and chemical
incompatibility with the electrodes.
This study, published in Nature Communications, reports
the development of a new family of materials that contains
suitable candidates for both the electrode and the electrolyte.
This leads to more compatible and stable interfaces between
the two. The research group used computational modelling to
design the materials by tweaking the chemical composition.
They then brought the materials to ISIS to confirm their
predictions using neutron diffraction and muon spectroscopy.
Their new materials take the perovskite structure, with
one containing tungsten and the other tellurium, leading to
excellent compatibility. Both contain a high concentration
of lithium ions in their crystal structure, which provides
fast lithium-ion diffusion. They found that, while tungsten
can readily change oxidation state – ideal for an electrode
– tellurium is resistant to redox cycling suitable for the
electrolyte. As well as testing the materials separately, the
group also combined them in a single hybrid solid-state cell,
and found that the electrode functionality was maintained.
Related publication: “Li1.5La1.5MO6 (M = W6+, Te6+) as a new series of lithium-rich double perovskites for
all-solid-state lithium-ion batteries.” Nature Communications, 11, 6392 (2020)