Lithium-sulfur battery

Lithium-sulfur battery inducing 3D growth of Li2S using weakly adsorbing metal oxide cathodes and high-donor-number electrolytes

This technology utilizes the synergy between metal oxides that weakly adsorb lithium polysulfides (LiPS), such as nickel oxide (NiO) and magnesium oxide (MgO), and electrolytes with high donor numbers to induce the growth of Li2S into 3D microparticles, preventing uneven passivation of the electrode surface.

In lithium-sulfur batteries, the shuttle effect occurs because LiPS easily dissolves into the electrolyte during charge/discharge cycles, and intermediate products have poor electrical conductivity. Furthermore, the discharge product, Li2S, accumulates as a 2D film, electrically insulating the electrode surface and significantly limiting sulfur utilization.

This technology incorporates NiO or MgO, which have a LiPS adsorption energy of less than 3.5 eV, into the cathode, and uses an electrolyte containing a first lithium salt, such as LiNO3, with a donor number of 15 kcal/mol or higher at a concentration of 0.5–1.8 M. It can be applied to the design of electrolytes and cathodes for high-capacity cells for EVs and ESS, as well as lightweight batteries for aviation and mobility, maximizing current transfer efficiency and sulfur utilization.

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Key Features:

• A cathode comprising a carbonaceous substrate, sulfur, and a metal oxide with an adsorption energy of less than 3.5 eV for lithium polysulfides.
• A metal oxide included in the cathode, selected from at least one of NiO or MgO, comprising 20 wt% to 50 wt% of the cathode weight.
• An electrolyte comprising a solvent, a first lithium salt with an anion donor number of 15 kcal/mol or higher, and a second lithium salt.
• A first lithium salt selected from LiNO3, LiBr, LiCl, LiI, LiCN, LiOAc, and LiOTf, included at a concentration of 0.5 M to 1.8 M.

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