Graphitized Carbon Xerogels for Lithium-Ion Batteries

Abstract

Carbon xerogels with different macropore sizes and degrees of graphitization were evaluated as electrodes in lithium-ion batteries. It was found that pore structure of the xerogels has a marked effect on the degree of graphitization of the final carbons. Moreover, the incorporation of graphene oxide to the polymeric structure of the carbon xerogels also leads to a change in their carbonaceous structure and to a remarkable increase in the graphitic phase of the samples studied. The sample with the highest degree of graphitization (i.e., hybrid graphene-carbon xerogel) displayed the highest capacity and stability over 100 cycles, with values even higher than those of the commercial graphite SLP50 used as reference.

A Promising Silicon/Carbon Xerogel Composite for High-Rate and High-Capacity Lithium-Ion Batteries

“…and macropore volumes are 1.71, 0.05 and 1.66 cm 3 g − 1 , respectively, and there is a narrow distribution of pore size centred on 275 nm. These results are similar to those for related materials [18].…”

“…0.338 nm (GXGO) vs. 0.335 nm (graphite), and its main crystallite size along the c-axis (L c ~ 12.8 nm) is higher than those determined for carbon xerogels [17]. These results confirm the graphitization of the xerogel, which is favored by the addition of GO to the xerogel precursor solution [18] and the subsequent thermal and mechanical treatment achieves greater uniformity of the graphitic laminates in the composite, as shown in Fig. 1.…”

“…In previous studies, our group found that the incorporation of GO in the polymeric precursor of the xerogels leads to a considerable change in their structure. This was due to the fact that graphene layers act as seeds, which promote the graphitization process, resulting in a more laminar structure [18]. In the diffractogram of 50Si/GXGO composite, a combination of peaks attributed to GXGO and nSi are clearly visible.…”

“…Some authors have incorporated highly conductive additives into the xerogel matrix to enhance electron mobility [13][14][15][16]. Others have prepared graphitic-type structural ordered carbon xerogels with improved electrical conductivity by microwave heating or by high temperature treatment using a graphene oxide as an additive [17][18][19], these materials have been investigated as anode materials for LIBs.…”

Influence of Resorcinol to Sodium Carbonate Ratio on Carbon Xerogel Properties for Aluminium Ion Battery

“…The diffractograms of CXG 500–2500 were very similar to each other with small differences of several hundred counts which indicated a similar structure. The calculated d 002 values for all CXG samples varied between 3.6–3.8 Å, values which were comparable to those extracted from plots of pyrolyzed resorcinol-formaldehyde resins (3.4–4.1 Å) [ 46 , 50 , 51 , 52 , 53 ]. Interestingly, the interspacing values of as-prepared CXG were 8–14% higher than those of natural graphite which might be advantageous for the intercalation of large AlCl 4 − anions.…”