Advancements in battery technology are important as energy storage systems emerge as essential in this technological age. Electrolyte additives merit special mention for their capacity to improve battery efficiency, safety, and life. In this blog, we explore the classifications and myriad benefits these remarkable compounds offer while focusing on MSE Supplies' selection of high-performance electrolyte additives.

Classifications of Electrolyte Additives

1. Unsaturated Carbonate Derivatives

These unsaturated carbonate derivatives, such as vinylene carbonate (C3H2O3), Diethyl Carbonate (DEC, C5H10O3) and ethylene carbonate (C3H4O3), are well known for their ability to form stable solid electrolyte interphase (SEI) layers on anode surfaces. Not only does this film protect the anode, by reducing the microstructure of the anode, but it also improves the cycling performance and Coulombic efficiency of the battery. However, these additives raise the impedance of the battery at high concentrations. For instance, VC forms a dense protective film through polymerization, and FEC provides a LiF-rich layer causing a uniform lithium deposition and suppressing the dendrite growth.

2. Ester-Based Additives

Ester-based additives include sulfur-containing compounds like 1,3-propane sultone (PS) and phosphate esters such as lithium fluorophosphate (LiDFP). These additives improve ionic conductivity, impedance, and thermal stability, which promote SEI and CEI films. Excellent cycling life is achieved using sulfur-based esters that are relatively immune to structural damage and electrolyte decomposition. Phosphate esters also act as dual-functional additives, as flame retardants and stabilize the electrode/electrolyte interface. 

3. Boron-Based Additives

Trimethylsilyl borate (TMSB) and tetraethylammonium tetrafluoroborate (TEABF6) are essential boron-based additives for high-voltage battery systems. They facilitate the dissociation of lithium salts and reduce the formation of by-products like LiF and PF5. As a result, the interfacial impedance is reduced and cycling stability is enhanced. Additionally, these additives give rise to robust CEI films while maintaining ionic conductivity and prolonging battery life.

4. Silicone Additives

Silicone-based additives such as MSTFA and BTA are effective in eliminating adverse damage from water and HF in electrolytes. These additives form high-quality SEI and CEI films and increase cycling stability, thus enabling batteries to cycle reliably under extreme temperatures and pressures. They also function multifunctionally, eliminating the corrosive ones and stabilizing the electrolyte structure.

5. Fluorine-Containing Additives

Fluoroethylene carbonate (FEC) and N,N-dimethyltrifluoromethanesulfonamide (C3H6F3NO2S), and other fluorine-containing additives, are popular for their promotion of LiF-rich SEI formation. Adding these inert, thermally conductive and electrically insulating additives leads to uniform lithium deposition, compatibility with high-voltage cathodes and better performance in extreme conditions. However, they have unique chemical properties that make them essential to the development of high energy density and long-lasting battery systems.

6. Alkali Metal Ion Additives

Electrostatic shielding layers on the electrode surface are formed by alkali metal ion additives (Cs+ or K+) salts to inhibit dendrite growth. By doing so, the uniform lithium deposition ensures the battery's safety and longevity.

7. Novel Additives

New innovative additives, like 4,6-dimethyl-2-mercaptopyrimidine (DMP), are being engineered to break through the barriers in lithium-ion batteries. By modifying lithium solvation structures, suppressing side reactions, and promoting homogeneous lithium deposition, these additives make next-generation energy storage solutions a reality.

Benefits of Electrolyte Additives

Electrolyte additives provide several advantages that drive advancements in battery technology. These compounds stabilize the electrode/electrolyte interface, extending battery lifespans and cycling stability. Dendrite suppression and formation of thick, robust SEI/CEI layers suppress thermal runaway and short-circuit risks. Improving ionic conductivity also improves charge/discharge rates and overall performance, but at the expense of additives. They also boost thermal resilience to permit batteries to work properly in extreme temperatures. Combined, these reasons make electrolyte additives indispensable to advancing energy storage.

MSE Supplies' Electrolyte Additive Selection

The Electrolyte Additives we offer at MSE Supplies are designed to meet the requirements of modern battery technologies and span a broad range of high-purity possibilities. The additives we carefully select are unmatched for their quality and reliability no matter whether you want to develop lithium-ion batteries, explore solid-state systems, or overcome high voltage challenges. It features from unsaturated carbonate derivatives to fluoride-containing compounds, to enable your innovation in energy storage.

Electrolyte additives have revolutionized the battery industry, solving performance, safety, and longevity concerns. Partnering with MSE Supplies means that you have premium materials and equipment at your fingertips to promote the success of your energy storage projects. Find what you need with our electrolyte additive catalog, or reach out to us for help choosing the right materials for your work.

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Sources:

1. Lei, Y., Wang, K., Jiang, S., Xu, X., Zheng, J., Yin, J., & Gao, Y. (2024). Recent progress on Multifunctional electrolyte Additives for High‐Energy‐Density Li Batteries – a review. ChemElectroChem, 11(14). https://doi.org/10.1002/celc.202300702