High capacitance of coarse-grained carbide derived carbon electrodes

Dyatkin, B. L.; Gogotsi, Oleksiy; Malinovskiy, Bohdan; Zozulya, Yuliya; Simon, Patrice; Gogotsi, Yury

doi:10.1016/j.jpowsour.2015.11.099

Cited by 69 publications

(43 citation statements)

References 55 publications

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“…The material is annealed for 2 h at 600°C under H 2 to remove traces of chlorine and other surface groups [71]. Electrochemical tests are performed using a two-electrode Swagelok cell.…”

Section: B Electrochemistry Experimentsmentioning

confidence: 99%

Blue Energy and Desalination with Nanoporous Carbon Electrodes: Capacitance from Molecular Simulations to Continuous Models

et al. 2018

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Capacitive mixing (CapMix) and capacitive deionization (CDI) are currently developed as alternatives to membrane-based processes to harvest blue energy-from salinity gradients between river and sea waterand to desalinate water-using charge-discharge cycles of capacitors. Nanoporous electrodes increase the contact area with the electrolyte and hence, in principle, also the performance of the process. However, models to design and optimize devices should be used with caution when the size of the pores becomes comparable to that of ions and water molecules. Here, we address this issue by simulating realistic capacitors based on aqueous electrolytes and nanoporous carbide-derived carbon (CDC) electrodes, accounting for both their complex structure and their polarization by the electrolyte under applied voltage. We compute the capacitance for two salt concentrations and validate our simulations by comparison with cyclic voltammetry experiments. We discuss the predictions of Debye-Hückel and Poisson-Boltzmann theories, as well as modified Donnan models, and we show that the latter can be parametrized using the molecular simulation results at high concentration. This then allows us to extrapolate the capacitance and salt adsorption capacity at lower concentrations, which cannot be simulated, finding a reasonable agreement with the experimental capacitance. We analyze the solvation of ions and their confinement within the electrodes-microscopic properties that are much more difficult to obtain experimentally than the electrochemical response but very important to understand the mechanisms at play. We finally discuss the implications of our findings for CapMix and CDI, both from the modeling point of view and from the use of CDCs in these contexts.

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“…The material is annealed for 2 h at 600°C under H 2 to remove traces of chlorine and other surface groups [71]. Electrochemical tests are performed using a two-electrode Swagelok cell.…”

Section: B Electrochemistry Experimentsmentioning

confidence: 99%

Blue Energy and Desalination with Nanoporous Carbon Electrodes: Capacitance from Molecular Simulations to Continuous Models

et al. 2018

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“…For instance, the pore length in a typical simulation is tens of nanometers at best, while in the experimental systems the pores can be micrometer long, as follows from the carbon particle sizes (see, e.g., Refs. [20,21], and Ref. [22]); likewise, the size of the region between the electrodes is of the order of nanometers in simulations, but it is hundreds of micrometers or millimeters in real supercapacitors.…”

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confidence: 99%

The effect of finite pore length on ion structure and charging

Breitsprecher

Abele

Kondrat

et al. 2017

The Journal of Chemical Physics

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Nanoporous supercapacitors play an important role in modern energy storage systems, and their modeling is essential to predict and optimize the charging behaviour. Two classes of models have been developed that consist of finite and infinitely long pores. Here, we show that although both types of models predict qualitatively consistent results, there are important differences emerging due to the finite pore length. In particular, we find that the ion density inside a finite pore is not constant, but increases linearly from the pore entrance to the pore end, where the ions form a strongly layered structure. This hinders a direct quantitative comparison between the two models. In addition, we show that although the ion density between the electrodes changes appreciably with the applied potential, this change has a minor effect on charging. Our simulations also reveal a complex charging behaviour, which is adsorption-driven at high voltages, but it is dominated either by co-ion desorption or by adsorption of both types of ions at low voltages, depending on the ion concentration.

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“…Carbides, such as TiC, SiC, B 4 C, and Mo 2 C, have been used as precursors to prepare CDCs for SC applications due to their simple preparation and desired porosity [47,171]. CDCs are commonly produced through selectively removing metal or metalloid atoms from carbide lattices by treating in hot halogens, which leads to the formation of porous carbon network [172,173].…”

Section: Carbide-derived Carbonsmentioning

confidence: 99%

Recent progress in carbon-based nanoarchitectures for advanced supercapacitors

Ran

Yang

Shao

2018

Adv Compos Hybrid Mater

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Supercapacitors, possessing high power densities, have been supposed to be one of the promising energy storage devices. Among various electrode materials of supercapacitors, carbon materials with porous nanostructure are considered as the emerging and promising candidates. This feature article reviewed the recent advances in different dimensional carbon-based nanoarchitectures for supercapacitors and particularly addressed the novel synthetic strategies to improve the electrochemical performances and corresponding theoretical foundations. The state-of-the-art progress was discussed, and diverse challenges for the electrochemical properties of carbon-based materials were propounded. Furthermore, perspectives for the design and assembly of advanced carbon-based nanoarchitectures for the supercapacitor electrode materials were highlighted.

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High capacitance of coarse-grained carbide derived carbon electrodes

Cited by 69 publications

References 55 publications

Blue Energy and Desalination with Nanoporous Carbon Electrodes: Capacitance from Molecular Simulations to Continuous Models

Blue Energy and Desalination with Nanoporous Carbon Electrodes: Capacitance from Molecular Simulations to Continuous Models

The effect of finite pore length on ion structure and charging

Recent progress in carbon-based nanoarchitectures for advanced supercapacitors

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