TPP (Tripropargyl Phosphate, >99.0%) as Battery Electrolyte Additive, 5 g/bottle, CBEATPP

Tripropargyl Phosphate (TPP)—systematically named tri(prop-2-yn-1-yl) phosphate—is a multifunctional phosphate ester additive combining three reactive alkyne (propargyl) groups with a central phosphate core (O=P(O-CH2-C≡CH3). It is widely used as a high-performance, film-forming additive, flame retardant, and structural stabilizer in non-aqueous electrolytes for high-voltage lithium-ion (LIBs), lithium-metal, and post-lithium battery systems. The core functional roles & electrochemical advantages are shown below:

Robust Cathode Electrolyte Interphase (CEI) Formation: High-voltage operation (>4.4 V vs. Li/Li+) accelerates conventional carbonate solvent oxidation at cathode surfaces. Due to its lower Highest Occupied Molecular Orbital (HOMO) energy level compared to standard carbonates, TPP oxidizes preferentially on nickel-rich cathodes (e.g., NMC811, NCMA) and high-voltage cobalt-free/spinel cathodes. Ring-opening and radical polymerization of the three carbon-carbon triple bonds (C≡C) yield a dense, highly cross-linked, phosphorus- and organic-rich CEI layer. 

Transition Metal Coordination & Dissolution Suppression: The electron-rich phosphate carbonyl oxygen (P=O) and alkyne moieties coordinate with catalytic transition-metal sites (Ni^{3+}/Ni^{4+}, Mn^{3+}) on cathode surfaces. This passivates active surface defect sites, suppressing transition-metal leaching, structural phase transitions (e.g., layered-to-rocksalt phase transformation), and subsequent metal ion migration to the anode.

Inelastic Poly-Alkyne SEI on Anodes: TPP also participates in sacrificial reduction on graphite or lithium-metal anodes at potentials around 1.3 V to 1.5 V vs. Li/Li+. The three propargyl arms polymerize into a flexible, conductive organic-inorganic interphase that promotes uniform Li+ ion flux and inhibits dendritic lithium growth.

Flame Retardancy & Thermal Stability Enhancement: Like other organic phosphate esters, the phosphate group (PO4)^{3-}-like core) acts as a radical scavenger in the gas phase during thermal abuse events. It suppresses electrolyte flammability and reduces self-extinguishing time (SET), improving overall battery safety under elevated temperatures (55-60°C).

Part Number	CBEATPP (C-BEA-TPP)
CAS	1779-34-6
Chemical Formula	C9H9O4P
Appearance	Colorless Liquid
Purity	>99.0% (moisture sensitive)
Molecular Weight	212.14 g/mol
Package Size	5 g/bottle

Notes: Please try to store the TPP liquid in a dry place (glovebox is the best)

References: 

1. Y. Qian, et al. Mechanism Study of Unsaturated Tripropargyl Phosphate as an Efficient Electrolyte Additive Forming Multifunctional Interphases in Lithium Ion and Lithium Metal Batteries, ACS Appl. Mater. Interfaces (2020) 12 (9): 10443–10451.
2. Y. Xie, et al. Thermochemical Crosstalk in Si-C Anodes: Mechanism and Stabilization via a Polymerizable Phosphorus-Based Additive, Adv. Energy Mater., 2026, 16, e04167