Electrochemical Properties and Structure Evolution of Starch-Based Carbon Nanomaterials as Li-Ion Anodes with Regard to Thermal Treatment

Abstract

The influence of the pyrolysis temperature on the structural, textural, and electrochemical properties of carbon aerogels obtained from potato, maize, and rice starches was analyzed. The carbonization of organic precursors, followed by gelatinization, exchange of solvent, and drying process, was carried out in an argon atmosphere at temperatures ranging from 600 °C to 1600 °C. The nanostructured carbons were characterized by X-ray powder diffraction (XRD) as well as N2-adsorption/desorption (N2-BET) methods. The electrochemical behavior of Li-ion cells based on the fabricated carbon anodes was investigated using the galvanostatic charge/discharge tests (GCDT) and electrochemical impedance spectroscopy (EIS). The results show that the thermal treatment stage has a crucial impact on the proper formation of the aerogel material’s porous structures and also on their working parameters as anode materials. The highest relative development of the external surface was obtained for the samples pyrolysed at 700 °C, which exhibited the best electrochemical characteristics (the highest specific capacities as well as the lowest charge transfer resistances).

Nitrogen-Doped Carbon Aerogels Derived from Starch Biomass with Improved Electrochemical Properties for Li-Ion Batteries

“…For all CAG cells, low values of initial Coulombic efficiency (CE) are observed. This capacity loss is typical for starch-based carbon aerogel materials [17][18][19][20][21] and can be attributed to the side reactions, such as SEI film formation at the electrode-electrolyte interface or the irreversible reaction of Li + with residual oxygenated functional groups at these carbon surfaces. However, with the increase of nitrogen in the investigated samples, a The nitrogen-doped carbon aerogel materials, as well as the pristine ones (CAGPS), were subjected to galvanostatic charge-discharge tests in a half-cell system.…”

“…All these aspects must be considered to fully explain the improvement of N-doped aerogel materials. Most suitable for high-capacity lithium storage (also confirmed by earlier research [49,50]) is pyridinic carbon, which is responsible for the enhancement of Li storage and more helpful for increasing reversible capacity than other types of N-dopants (like N-5, NQ) [45,51] To obtain carbon aerogel (CAGPS sample) and nitrogen-doped carbon materials (MCAGPS-N and CAGPS-N samples), proper compositions of polymeric carbohydrate (potato starch, Sigma-Aldrich, Saint Louis, MO, USA) were, in short, processed by gelatinization route followed by the pyrolysis of organic precursors under an ambient atmosphere (Ar for CAGPS and MCAGPS-N samples and N 2 for CAGPS-N sample) at 700 • C, according to the method reported in our previous studies [17][18][19][20][21]. Importantly, and applicable to MCAGPS-N samples, is the fact that the main precursor of carbon materials-potato starch, was modified with the addition of varied melamine (Acros Organics, Belgium, 99%) concentrations (1%, 5%, and 20 wt.…”

“…Many different types of natural sources, such as starch [6][7][8], cellulose [9], lignin [10], corn products [11,12], palm spathe [13], bamboo chopsticks [14], coffee grounds [15], and mushrooms [16], have been employed so far to prepare carbon anode materials with distinctive performance, which makes biopolymer precursors promising resources for the preparation of carbon material with a view to apply them in lithium-ion batteries. Our previous research demonstrated that the use of starch is particularly interesting [17][18][19][20]. The idea of such a concept-apart from the fact that starch is a widely available, renewable, and affordable raw material that forms products Int.…”

“…Many different types of natural sources, such as starch [ 6 , 7 , 8 ], cellulose [ 9 ], lignin [ 10 ], corn products [ 11 , 12 ], palm spathe [ 13 ], bamboo chopsticks [ 14 ], coffee grounds [ 15 ], and mushrooms [ 16 ], have been employed so far to prepare carbon anode materials with distinctive performance, which makes biopolymer precursors promising resources for the preparation of carbon material with a view to apply them in lithium-ion batteries. Our previous research demonstrated that the use of starch is particularly interesting [ 17 , 18 , 19 , 20 ]. The idea of such a concept—apart from the fact that starch is a widely available, renewable, and affordable raw material that forms products of green technology with zero carbon footprint—has its justification in the wide diversity of this polymer, depending on the botanical origin (concerning a different proportion of amylose and amylopectin as well as the different length of the polymer chain in various types of starch).…”

The Electrochemical Stability of Starch Carbon as an Important Property in the Construction of a Lithium-Ion Cell

“…Swelling of granules, gelling, or retrogradation are important processes that allow the use of starch in the appropriate form as electrode material in lithium-ion cells. This enables a multiple increase in the stability of the capacity and the Coulombic efficiency of the cell [ 4 , 5 , 6 ]. Anode materials determine the storage capacity of the cells.…”