Dilithium benzenedipropiolate was prepared and investigated as a potential negative electrode material for secondary lithium-ion batteries. In addition to the expected reduction of its carbonyls, this material can reduce and reversibly oxidize its unsaturated carbon−carbon bonds leading to a Li/C ratio of 1/1 and a specific capacity as high as 1363 mAh g −1 : the highest ever reported for a lithium carboxylate. Density functional theory calculations suggest that the lithiation is preferential on the propiolate carbons.

Organic compounds are increasingly being investigated as electrode materials for Li-or Na-ion batteries. Even though their gravimetric capacity can challenge that of their inorganic counterparts, a number of problems need further attention, not least their chemical and electrochemical stability toward the electrolyte systems. There has been speculation that several of these issues have their origin in the formation of a less stable solid electrolyte interphase (SEI) layer and its evolution during battery cycling. We here present the very first thorough characterization of the organic electrode material SEI layer using hard X-ray photoelectron spectroscopy (HAXPES), for both Li-and Na-based electrodes. Dilithium and disodium benzenediacrylates have been used for battery construction and investigated electrochemically followed by HAXPES measurements after contact with the electrolyte and after cycling. The Na-based electrodes react spontaneously with the electrolyte, and the SEI layer is dominated by inorganic species with continuous salt degradation during cycling. The Li-based electrodes display an SEI layer with primarily organic species from solvent degradation products appearing only after cycling and increasing in amount with the number of electrochemical cycles.

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This work presents the synthesis and characterization of a novel organic Li-battery anode material: dilithium 2-aminoterephthalate (C8H5Li2NO4). When investigated in Li half-cells, the resulting electrodes show stable capacities around ca. 180 mAh g -1 and promising rate capabilities, with battery performance at 500 mA g -1 and good capacity recovery, despite being an asymmetric compound. DFT calculations indicate a preferential lithiation on carboxylates close to the amino group.