Empowering organic‐based negative electrode material based on conjugated lithium carboxylate through molecular design

Abstract

In this article, we describe the design and gram‐scale synthesis of a new anthracene‐based negative electrode material for Li‐ion batteries. Based on rational design, featuring a strong electronic delocalization and a long conjugation length, this material has power performance to date unmatched for a conjugated lithium carboxylate, displaying a gravimetric capacity of 150 mAh g−1 at a cycling rate of 20 Li+/h (10 C) without any electrode engineering. Additionally, to the design, partial solubility of the fully reduced phase may also explain the electrochemical performances obtained at a low and high rate.

Organic Negative Electrode Materials for Metal‐Ion and Molecular‐Ion Batteries: Progress and Challenges from a Molecular Engineering Perspective

“…Very recently, thanks to an important effort on organic synthesis (seven steps synthetic procedure), the most extended conjugated structure so far, anthracene, was applied as core unit for conjugated dicarboxylates and investigated in Li half-cells. [148] The simple addition of an aromatic ring (from naphthalene to anthracene) showed a significant impact on the rate capability without any influence on the redox potential, as Li 2 -ADC was found to be reduced at a potential of ≈0.81 V versus Li + /Li. Rate capability revealed to be enhanced as well, since the compound www.advancedsciencenews.com was able to maintain 84% of its capacity (162 mAh g −1 , considered as of 2 Li + /e − ) at a high cycling rate rarely reported for a dicarboxylate-based material in Li half-cells, namely 20 Li + /h.…”

“…As a result of their first experimental finding, Fédèle et al [141] have extensively investigated the aromatic extension with the purpose of enhancing the rate capability of conjugated dicarboxylates (Figure 3). Naphthalene, biphenyl, perylene, and anthracene have been employed as core units, within dilithium 2,6-naphthalenedicarboxylate (denoted Li 2 -NDC), [103,104,141,142] dilithium 4,4'-biphenyldicarboxylate (denoted Li 2 -BPDC), [143] tetralithium perylenetetracarboxylate (denoted as Li 4 -PTC), [87,[144][145][146][147] and dilithium 2,6-anthracenedicarboxylate (denoted Li 2 -ADC), [148] respectively. All the dicarboxylate derivatives have been electrochemically evaluated in Li half-cells using rigorously the same conditions, namely hand mixing of 60% of active material with 40% of conductive carbon (Super P) and mass loading of about 10 mg.…”

“…Whereas most of the reported carboxylate precursors are commercially available and can be obtained through facile acid-base reaction, harsh synthetic procedures (e.g., multistep synthesis involving environmentally non-benign solvents) might be required for additional designs as already reported for new dicarboxylate structures. [148,200,201,219] Of course organic chemical composition would win on sustainability criteria against its inorganic counterpart; but source of precursor, synthesis process, and recyclability are also important parameters to be considered if we want to promote the true sustainability. In this connection, possible options to be explored could include eco-friendly synthetic processes, via for example chemical CO 2 sequestration (retro-Kolbe-Schmitt) [36,196] and recyclability of Li through combustion at moderate temperatures.…”

N‐Substituted Carbazole Derivate Salts as Stable Organic Electrodes for Anion Insertion

“…The first strategy involves the adjunction of an insoluble fragment directly on the molecule backbone (Approach 1). Even if in some cases the presence of this type of fragment is not sufficient to completely prevent the solubility, [24] this strategy proved to be effective with various redox center such as quinones or phenothiazines. [15,25] A second less developed approach is based on the formation of well-defined oligomers like dimers or trimers (Approach 2).…”

Structure–property relationships in organic battery anode materials: exploring redox reactions in crystalline Na- and Li-benzene diacrylate using combined crystallography and density functional theory calculations

“…[10][11][12][13][14][15] Among these, conjugated carboxylates have become one of the most promising candidates due to the stability against dissolution in organic electrolytes while providing reasonable energy density. Not least have carboxylate-based molecules been explored as LIB anodes, [16][17][18][19][20] with some of them exhibiting an impressive capacity due to the stabilization of the so-called 'superlithiation' phase. [21][22][23] Despite being a very promising class of materials to be employed in environmentally friendly ESS, organic electroactive materials have some hurdles to be overcome to enable application in commercial devices.…”