PDTD (4-Propyl-1,3,2-dioxathiolane 2,2-dioxide, or PEGLST, >99.5%) as Battery Electrolyte Additive, 10-50 g/bottle, CBEAPDTD

PDTD—systematically named 4-propyl-1,3,2-dioxathiolane 2,2-dioxide (or propyl ethylene sulfate, also called PEGLST)—is an alkyl-substituted cyclic sulfate functional additive. It belongs to the same family of cyclic sulfate film-formers as ethylene sulfate (DTD) and propylene sulfate (MDTD), engineered to improve interphase stability in high-voltage lithium-ion (LIB), lithium-metal, and sodium-ion batteries.

Sacrificial Reduction & Conductive Inorganic SEI: PDTD possesses a higher reduction potential (~ 1.3 V to 1.4 V vs. Li/Li+) than baseline cyclic/linear carbonate solvents (EC, DMC, EMC). It reduces preferentially on graphite, silicon-carbon, or metal anodes via ring-opening cleavage of C–O and S–O bonds. This generates an inorganic-rich Solid Electrolyte Interphase (SEI) composed of lithium sulfate (Li2SO4), lithium sulfite (Li2SO3), and alkyl sulfates.

High-Voltage Cathode Passivation (CEI): PDTD participates in sacrificial oxidative decomposition on cathode surfaces at high operating potentials (>4.4 V vs. Li/Li+). The resulting Cathode Electrolyte Interphase (CEI) passivates surface catalytic sites, suppressing transition-metal leaching (Ni^{3+}/Ni^{4+}, Co^{3+}, Mn^{3+}) and preventing electrolyte oxidation on nickel-rich cathodes (such as NMC622/NMC811) and high-voltage LiCoO2 (LCO).

Low Melting Point & Superior Solubility (Advantage over DTD): Unsubstituted ethylene sulfate (DTD) has a high melting point (~ 95–97°C) and limited solubility in linear carbonates at low temperatures. The longer aliphatic propyl side chain breaks molecular symmetry, giving PDTD a much lower melting point and enhanced solubility in liquid carbonate blends. This ensures stable low-temperature performance and avoids additive crystallization.

Lower Charge-Transfer Resistance & Coulombic Efficiency: The sulfur-rich interphases derived from cyclic sulfates exhibit high ionic conductivity for Li+ or Na+ ions, lowering charge-transfer impedance at the electrode interface. PDTD significantly boosts initial Coulombic efficiency (ICE) and extended cycling capacity retention in full cells.

Part Number	CBEAPDTD (C-BEA-PDTD)
CAS	165108-64-5
Chemical Formula	C5H10O4S
Appearance	Colorless Liquid
Purity	>99.5%
Molecular Weight	166.20 g/mol
Package Size	10 g, 25 g, and 50 g/bottle

Notes: Please store the PDTD solution in a dry place (glovebox is the best).

References: 

1. S. Wu, et al. Stabilizing LiCoO2/Graphite at High Voltages with an Electrolyte Additive, ACS Appl. Mater. Interfaces (2019) 11 (19): 17940–17951
2. Y. Lin, et al. Insight into the Mechanism of Improved Interfacial Properties between Electrodes and Electrolyte in the Graphite/LiNi0.6Mn0.2Co0.2O2 Cell via Incorporation of 4‑Propyl-[1,3,2]dioxathiolane-2,2-dioxide (PDTD), ACS Appl. Mater. Interfaces (2018) 10 (19): 16400–16409