Ethylene sulfate

Example

Use in Lemonergy

Connect transport with electronic isolation.

This is a reference concept. No executable Lemonergy block has been verified for this term.

Connected concepts

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Electrolyte additive

A compound added to the electrolyte at a few percent to improve one property — vinylene carbonate and fluoroethylene carbonate build a tougher SEI, others suppress gassing or overcharge. Additive packages are among a cell maker’s closest secrets.

Formation

The first controlled charge and discharge cycles of a newly assembled cell, during which the SEI forms. It is part of cell production, before aging and grading.

Impedance rise

An increase in a cell’s internal resistance as it ages. It costs voltage under load and therefore power, even while the stored charge is still there.

Lithium difluorophosphate

A salt-type additive, LiPO₂F₂, used at around 1 % because it dissolves only sparingly in carbonate solvents. It forms thin phosphate-rich films on both electrodes that lower interfacial resistance, improving low-temperature power and high-voltage cycling. Small amounts also form naturally when LiPF₆ meets traces of water.

Solid–electrolyte interphase

A film of electrolyte reaction products on the negative-electrode particles — graphite, and also silicon or lithium metal. It protects the electrode from further reaction but grows slowly for the whole life of the cell, consuming cyclable lithium.

Vinylene carbonate

The most common SEI-forming additive, used at 1–3 %. It is reduced before the solvent on the first charge and polymerises into a thinner, more flexible SEI that lengthens cycle life.

References & further reading

Further reading on this topic

These sources provide broader context; they are not presented as citations for every statement in this entry.

1. Electrolytes and Interphases in Li-Ion Batteries and Beyond

   Kang Xu · Chemical Reviews · 2014

   Topic background · Electrolyte salts, solvents, additives and electrode interphases.