Sony working on new lithium-sulfur batteries with 40% more capacity

Sony is reportedly working on new sulfur-based batteries which offer 40% better energy density per volume than Li-ion batteries.

Japanese newspaper Nikkei said in a report that Sony hopes to replace today’s lithium-ion batteries with lithium-sulfur batteries and expects to begin commercial production of the new batteries in 2020.

The company plans to use a sulfur (S) compound as an electrode material, increasing energy density per volume from 700Wh/L to 1,000Wh/L.

Metal lithium will be used for the negative electrode, which despite being known as “the material of dreams”, has never been used for rechargeable batteries due to the high difficulty.

The reason why it’s so hard to work with metal lithium as a negative electrode is because of uncontrollable dendritic Li growth and limited Coulombic efficiency during Li deposition/stripping.

Sony is still working on solutions to the technical challenges of using sulfur and metal lithium, with Nikkei stating in its report that Sony’s lithium-sulfur batteries are still prone to “heat generation or ignition.”

The Nikkei report concluded: “Despite such difficulties, Sony considers that it is a promising technology to realize an energy density of 1,000Wh/L in about 2020.”