Among battery materials, the electrolyte serves as a medium that enables lithium-ions to move stably between the cathode and anode. As the applications of batteries expand and various performance requirements emerge, SAMSUNG SDI is improving battery characteristics through the development of diverse electrolytes.

In lithium-ion batteries, lithium-ions and electrons move to store or release electrical energy. Here, the electrolyte plays a crucial role in facilitating the movement of lithium-ions during this process. 

Electrolytes are composed of lithium salts, organic solvents, and additives. Since the ionic conductivity* of lithium-ions varies depending on the type and composition of lithium salt and solvent, SAMSUNG SDI enhances battery performance by designing an optimal electrolyte composition.

* Ionic conductivity: the rate of ionic transport in the electrolyte.

[Electrolytes serve as a medium for facilitating the movement of lithium-ions]

The electrolyte not only serves as a medium for the movement of lithium-ion but also plays a critical role in maintaining battery stability. 

In lithium-ion batteries, repeated charging and discharging cause side reactions at the interfaces of the cathode and anode, making long-term use more challenging. To suppress these side reactions, the electrolyte forms protective layers—known as the Cathode Electrolyte Interphase (CEI*) and the Solid Electrolyte Interphase (SEI*)—on the surfaces of the cathode and anode. These layers help ensure battery stability and long lifespan. 

* CEI and SEI layers : Thin films that form on the surfaces of electrode materials. The CEI forms on the cathode side, while the SEI forms on the anode side.

[Electrolytes form protective layers on the surface to ensure battery stability and long lifespan.]

Electrolyte additives are also used to enhance battery cell performance. These additives are developed to improve specific properties—such as reducing internal resistance or maintaining thermal stability—when combined with cathode and anode materials during cell design. SAMSUNG SDI actively researches and develops additives with its own technology to improve cell performance.

In addition to the liquid electrolyte currently in use, SAMSUNG SDI is applying its proprietary solid electrolyte in all-solid-state batteries. The solid electrolyte serves as a substitute for the separator and contributes to higher energy density in all-solid-state batteries.

SAMSUNG SDI will continue to research and develop its proprietary electrolyte to enhance battery performance.