Computational Modelling — Overscreening-Driven Modulation of Ion Adsorption and Desorption in Conductive MOF Electrodes by Charging Rates

3 measurement groups · 16 results

Reported values remain attached to the sample, method, conditions, extraction quality and source location that produced them.

Dimensionless diffusion-time scaling between simulation and EQCM experiment

MD model of Ni3(HITP)2 electrodes in [EMIM][BF4] · Model

Simulation charging periods of 10-100 ns scaled using Lsim = 5.854 nm and Lexp between 5 and 62.5 um from c-MOF crystal alignment limits.

Geometry: c-MOF rods on quartz, average length about 250 nm and diameter about 20 nm
Context: model-to-experiment comparison for pristine Ni3(HITP)2 c-MOF electrode
Measurement source: 2588 · Methods - Linkage between Experiments and Simulations · Figure S16

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Estimated inside-pore surface area per c-MOF rod	about 209,043 nm^2	—	—	Text Approximate	2588 · Methods - Linkage between Experiments and Simulations · Figure S16
Estimated outside-pore surface area per c-MOF rod	about 16328 nm^2	—	—	Text Approximate	2588 · Methods - Linkage between Experiments and Simulations · Figure S16
Outside-pore surface-area fraction	about 7% of the total surface area	0.07 fraction	—	Text Approximate	2588 · Methods - Linkage between Experiments and Simulations · Figure S16
Maximum scaled simulation scan rate	137 V s^-1	—	—	Text Exact Reported	2588 · Methods - Linkage between Experiments and Simulations · Figure S16
Minimum scaled simulation scan rate	0.0877 V s^-1	—	—	Text Exact Reported	2588 · Methods - Linkage between Experiments and Simulations · Figure S16

Constant-potential molecular dynamics (CPM-MD) in customised GROMACS

Molecular dynamics

MD model of Ni3(HITP)2 electrodes in [EMIM][BF4] · Model

Coarse-grained [EMIM][BF4], UFF Lennard-Jones parameters for c-MOF atoms, 2 fs timestep, 1.2 nm cutoff, particle mesh Ewald with 0.12 nm FFT grid, NVT at 333 K with Nose-Hoover thermostat.

Temperature: 333
Atmosphere: NVT ensemble
Geometry: Simulation box 4.3794 x 3.79268 x 40 nm^3; each electrode has stacks of 18 c-MOF sheets of length 5.854 nm.
Context: model Ni3(HITP)2 electrodes in [EMIM][BF4]
Measurement source: 2587 · Methods - Molecular Dynamics Simulations · Figure 1b

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
MD simulation box x dimension	4.3794 nm	—	—	Text Exact Reported	2587 · Methods - Molecular Dynamics Simulations · Figure 1b
MD simulation box y dimension	3.79268 nm	—	—	Text Exact Reported	2587 · Methods - Molecular Dynamics Simulations · Figure 1b
MD simulation box z dimension	40 nm	—	—	Text Exact Reported	2587 · Methods - Molecular Dynamics Simulations · Figure 1b
Nonpolarized equilibration time before charging simulations	40 ns	—	—	Text Exact Reported	2588 · Methods - Molecular Dynamics Simulations
c-MOF sheets per MD electrode	18 c-MOF sheets	—	—	Text Exact Reported	2587 · Methods - Molecular Dynamics Simulations · Figure 1b
MD c-MOF sheet length	5.854 nm	—	—	Text Exact Reported	2587 · Methods - Molecular Dynamics Simulations · Figure 1b
MD timestep	2 fs	—	—	Text Exact Reported	2588 · Methods - Molecular Dynamics Simulations
c-MOF pore diameter used for surface-area estimateMarked as a best value within this paper	around 1.5 nm	—	—	Text Approximate	2588 · Methods - Linkage between Experiments and Simulations · Figure S16

MD number-density, radial-density and charge-density analysis

Molecular dynamics

MD model of Ni3(HITP)2 electrodes in [EMIM][BF4] · Model

Quasi-static single-sided electrode potentials from -0.75 to 0.75 V and cyclic triangular-wave potentials with periods of 100 and 10 ns; main comparison also uses -0.25 to 0.25 V.

Temperature: 333
Atmosphere: NVT ensemble
Geometry: Ni3(HITP)2 nanopores split into central and surface regions
Context: model Ni3(HITP)2 electrodes in [EMIM][BF4]
Measurement source: 2588 · Methods - Molecular Dynamics Simulations · Figures 2-4 and S4-S15

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Cyclic MD charging-discharging period, slower dynamic case	100 ns	—	—	Text Exact Reported	2588 · Methods - Molecular Dynamics Simulations · Figure S11
Cyclic MD charging-discharging period, faster dynamic case	10 ns	—	—	Text Exact Reported	2588 · Methods - Molecular Dynamics Simulations · Figure S11
Origin of anomalous cation increase	overscreening by anions near positively polarised electrode causes anomalous cation increase behind the anion layer	—	—	Text Qualitative	2586 · Results and Discussion · Figure 4