Alginic acid-derived mesoporous carbonaceous materials (Starbon®) as negative electrodes for lithium ion batteries: Importance of porosity and electronic conductivity

Abstract

Alginic acid-derived mesoporous carbonaceous materials (Starbon¨ A800 series) were investigated as negative electrodes for lithium ion batteries. To this extent, a set of mesoporous carbons with different pore volume and electronic conductivity was tested. The best electrochemical performance was obtained for A800 with High Pore Volume (A800HPV), which displays both the highest pore volume (0.9 cm 3 g-1) and the highest electronic conductivity (84 S m-1) of the tested materials. When compared to a commercial mesoporous carbon, A800HPV was found to exhibit both a better long-term stability, and a markedly improved rate capability. The presence of a hierarchical interconnected pore network in A800HPV, accounting for a high electrolyte accessibility, could lay at the origin of the good electrochemical performance. Overall, the electronic conductivity and the mesopore size appear to be the most important parameters, much more than the specific surface area. Finally, A800HPV electrodes display similar electrochemical performance when formulated with or without added conductive additive, which could make for a simpler and more eco-friendly electrode processing.

Dehydration of Alginic Acid Cryogel by TiCl4 vapor: Direct Access to Mesoporous TiO2@C Nanocomposites and Their Performance in Lithium‐Ion Batteries

“…TEM-EDX mapping (Figure 4d-f) revealed that both carbon and TiO 2 particles were homogeneously dispersed with no segregation. In the case of A600 ( Figure S5),T EM confirmed that the mesoporosity arose from the entanglement of bundles of AA chains (with a [58] present in the cryogel and maintained during carbonization. The Raman spectra of the samples before thermalt reatment did not present any signals that were clear or strong enough to be interpreted.…”

“…A small cathodic peak at 0.7 V, recorded only during the first cycle, was attributed to the decomposition of electrolyte on the surface of the electrode. In case of mesoporous carbonaceous material A600 (Figure c), the two cathodic peaks at 1.4 and 0.7 V during the first cycle were probably owing to irreversible reactions such as the reaction of lithium with oxygenated surface groups in A600 (1.4 V) and the decomposition of electrolyte (0.7 V), resulting in the formation of the SEI . These two peaks were not observed during the subsequent cycles, leaving only a peak at 0.1 V associated with the reversible insertion of lithium in amorphous carbon.…”

“…In the case of A600 (Figure S5), TEM confirmed that the mesoporosity arose from the entanglement of bundles of AA chains (with a thickness of ca. 15 nm) present in the cryogel and maintained during carbonization.…”

“…In case of mesoporous carbonaceousm aterialA 600 (Figure 8c), the two cathodic peaks at 1.4 and 0.7 Vd uring the first cycle were probably owing to irreversible reactions such as the reactiono fl ithium with oxygenated surfaceg roups in A600 (1.4 V) and the decomposition of electrolyte (0.7 V), resulting in the formation of the SEI. [58] These two peaks were not observed during the subsequent cycles,l eaving only ap eak at 0.1 Vassociated with the reversible insertion of lithium in amorphous carbon. After the second cycle,t he CV curves were almost identical, which confirmed that the structure of A600 andt he SEI formed at itss urface were stable, without any significant degradation during cycling.…”

Carbonization of polysaccharides in FeCl3/BmimCl ionic liquids: Breaking the capacity barrier of carbon negative electrodes in lithium ion batteries

“…Interconnected and hierarchical pore structures were shown to improve the diffusion of lithium ions, while high specific surface areas promote efficient charge-transfer processes at the electrode-electrolyte interface. [2,3] Note that such high surface area can also severely impact the efficiency of the first cycle. Different approaches and precursors were developed for the synthesis of advanced porous carbons with high specific surface areas and pore volumes.…”