Squaric Acid (C4H2O4, Quadratic Acid, >99.5%) as Precursor for Cathode Pre-Lithiation/Sodiation Additive (Li2C4O4 or Na2C4O4) Synthesis, 25-100 g/bottle, CCPLSAPCSA
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Squaric acid (3,4-dihydroxy-3-cyclobutene-1,2-dione, C4H2O4), frequently referred to in literature as quadratic acid, is a rigid, aromatic dicarboxylic carbon-oxygen precursor utilized in advanced energy storage research to synthesize high-capacity cathode pre-lithiation (and pre-sodiation) sacrificial salts—specifically dilithium squarate (Li2C4O4) and disodium squarate (Na2C4O4).In high-energy lithium and sodium metal-ion batteries, these squarate salts serve as sacrificial cathode additives that release active metal ions during initial charging to compensate for irreversible capacity loss (ICL) at the anode, leaving behind an inert, benign carbon-oxygen byproduct.
Its main functional roles in cathode pre-lithiation/sodiation are: (1) Compensation for Anode Irreversible Capacity Loss (ICL): During the first charge cycle, high-capacity anodes (such as silicon, hard carbon, or lithium/sodium metal hosts) consume a significant fraction of active ions to form the Solid Electrolyte Interphase (SEI). By blending 3–8 wt% of Li2C4O4 or Na2C4O4 directly into the cathode slurry, these excess ions are provided in situ, preventing first-cycle capacity drop and boosting full-cell Coulombic efficiency. (2) Controlled Sacrificial Gas Release: The oxidation of the squarate core occurs within a targeted voltage window during initial formation, allowing controlled gas venting prior to final cell sealing or via pouch-cell degassing steps, ensuring zero gas swelling during subsequent cycling.
| Part Number |
CCPLSAPCSA (C-CPLSA-PC-SA) |
| CAS |
2892-51-5 |
| Purity |
>99.5% |
| Appearance |
White Powder |
| Molecular Weight |
114.06 g/mol |
| Melt Point |
>300 °C |
| Package Grade |
25 g, 50 g, and 100 g/bottle |
Notes: Please store the squaric acid powder in a dry place.
References:
- A. Gomez-Martin, et al. Opportunities and Challenges of Li2C4O4 as Pre-Lithiation Additive for the Positive Electrode in NMC622||Silicon/Graphite Lithium Ion Cells, Adv. Sci., 2022, 9, 2201742
- B. Pal, et al. Extended Cycle Life in Lithium-Ion Batteries through Lithium Supplementation from Li2C4O4@SiO2 Microcapsules, Batteries & Supercaps, 2026, 9, e202500444