First principle and Atomistic simulation of transition metal compounds for battery application

First principles and Atomistic simulation of
transition-metal complexes for battery application
Asif Iqbal Bhatti
Grenoble INP Phelma
20th
December 2018
Asif Iqbal Bhatti (Grenoble INP Phelma) First principles and Atomistic simulation of transition-metal complexes for battery application20th December 2018 1 / 49

CONTENTS
Contents

INTRODUCTION Li-ion Batteries
Contents

INTRODUCTION Li-ion Batteries
Li-ion Batteries
Working mechanism of
Li-ion battery
Types of anode/cathode materials for Li-ion
batteries

INTRODUCTION Organic polymers
Cathode material: Organic polymers
Advantage
Low molecular weight
Rapid electron transfer kinetic
value ⇒ high capacity rate during
the charge/discharge process
Voltage & capacity can be tuned by
functionalization
Limitations
Low Cycling life and Structural
stability for some polymers

COORDINATION POLYMER
Contents

COORDINATION POLYMER Transition metal complexes
Metal Complexes as active Cathode materials
Combination of Ligand & Metal elements
Ability to vary degree of oxidation
And Voltage can be tuned according to electrolytic window
Coordination may show improved Structural Stability & Cycling life
Best candidate Fe, Ru, and Cu with bipyridine as a ligand

COORDINATION POLYMER Transition metal complexes
Bi-nuclear & Poly-nuclear structure

THEORETICAL FRAMEWORK
Contents

THEORETICAL FRAMEWORK Density functional theory
Kohn Sham Density Functional Theory (DFT)
EKS [ρ (r)] = Ts [ρ (r)] + ENe [ρ (r)] + EH [ρ (r)] + EXC [ρ (r)] (1)
Initial Guess ρ(r)
using LCAO: GTO
Calculate eﬀective potential
νeff
(r) = Ven
(r) + ∫ρ(r΄)/|r-r΄|dr΄ + VXC
[ρ(r)]
Kohn Sham Equations
[-ℏ2
/2me
∂i
2
+ νeff
(r)] φi
= εi
φi
Compute the Electron Density & Total Energy
ρ(r) = ∑i
|φi
(r)|2
→ Etot[ρ(r)] = ...
CONVERGED?
Output Quantities
ρ0
(r), Ei
[ρ0
(r)] → Forces, Eigenvalues, Frequencies
SCF
MeanFieldApproximationVXC
[ρ(r)] = δEXC
[ρ]/δρ(r)
©
Exact EXC [ρ] functional is not known => All DFT
methods are approximations of this functional
GGA (PBE)
EXC ≈ EGGA
XC [ρ] = ρ (r) XC (ρ (r) , ρ (r)) dr
Hybrid functionals (PBE0)
E
Hybrid
XC = aEHF
X + (1 − a)EDFT
X + EDFT
C
.
.
delocalized ﬆate
localized ﬆate

THEORETICAL FRAMEWORK Density functional theory
Modeling Fe & Ru complex

DENSITY FUNCTIONAL THEORY Structural properties
Finding the ground state structure for Fe & Ru complex
Exploration of configuration space
For Fe and Ru complex TFSI−
cis state is found to be the minima by ≈ 0.3 eV
0.03 eV
3.31 kJ/mol
cis
trans
Gasphaseoptimization

DENSITY FUNCTIONAL THEORY Structural properties
Geometrical parameters
Fe2+/3+
Un Loaded
Full loaded Ru2+/3+
Un loaded
Full loaded
Fe average geometrical parameters
Neutral
PBE PBE0 Exp
Fe − N 1.960 1.986 1.965
C1 − C1 1.468 1.471 1.472
N − C1 1.371 1.351 1.350
Full Loaded
PBE PBE0 Exp
1.971 1.971 1.960
1.465 1.467 1.473
1.369 1.356 1.350
Ru average geometrical parameters
Neutral
PBE PBE0 Exp
Ru − N 2.064 2.063 2.054
C1 − C1 1.471 1.471 1.474
N − C1 1.372 1.355 1.354
Full Loaded
PBE PBE0 Exp
2.069 2.063 2.056
1.469 1.467 1.450
1.372 1.357 -

DENSITY FUNCTIONAL THEORY Fe/Ru Electronic properties
PBE0: Fe2+
Partial Density Of States (PDOS) analysis
No ligand field picture observed
Ci1
Ci2
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
1.5
Occupied Orbitals
Virtual Orbitals
Energy (eV)
HOMO
PBE0: PDOS plot for Fe
2+
(dmbpy)3
2PF6
-
mono-nuclear complex
Fe atom
Ci1
Ci2
N atoms
C and H atoms

PBE0: Fe3+
PDOS analysis
No localization of states
Ci1
Ci2
Ci3
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
1.5
0.0
0.5
1.0
1.5
PBE0: DOS plot for Fe
3+
(dmbpy)3
3PF6
-
mono-nuclear complex
Occupied Orbitals
Virtual Orbitals
spin down channel
LUMOHOMO
Energy (eV)
spin up chanel
HOMO
Fe atom
Ci1
Ci2
Ci3
N atoms
C and H atoms

PBE: Fe2+
PDOS analysis
Ligand field picture observed
t2g
eg
∆o
=0.25 eV
Ci2
Ci1
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Occupied Orbitals
Virtual Orbitals
Energy (eV)
HOMO
PBE: PDOS plot for Neutral Mono-Nuclear complex
Ci1
Ci2
Fe atom
N atoms
C and H atoms

PBE: Fe3+
PDOS analysis
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
1.5
2.0
0.0
0.5
1.0
1.5
2.0
HOMO
Spin up channel
Spin down channel
LUMO
HOMO
Energy (eV)
Fe atom
N atoms
Ci1
Ci2
Ci3
C and H atoms
PBE: PDOS plot for Full loaded Mono-Nuclear complex
Occupied Orbitals
Virtuals Orbitals
t2g
eg
∆o
=0.62 eV
Ci1
Ci2
Ci3
Ligand field effect intact for PBE whereas PBE0 delocalizes the states

DENSITY FUNCTIONAL THEORY Cu Complex
Modeling the Cu complex

DENSITY FUNCTIONAL THEORY Cu Structural properties
Cu Configuration space & Ground state structure
Large conformational change: Deep
drawback for battery materials
For quick charge/discharge the
kinetics effects on compound
should be less
Less conformational change during the
oxidation step ⇒ the easier the
electron transfer (k0
)
105.0
151.6 81.9
Unloaded
Full Loaded
φo
θ
Cu+
/Cu2+
124.4o
125.7o
81.6o
Without Counter-ions
N
Cu
UnLoaded Full Loaded
Ci1
Ci2
Cu
122.0
80.2
137.2
107.6
80.2
97.3
N
With Counter-ions

DENSITY FUNCTIONAL THEORY Cu Electronic properties
PBE: Cu PDOS analysis
Peak shows not a regular tetrahedral geometry
Hybridization with counter-ions
Forms the pentavalent coordination
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
Virtual Orbitals
Occupied Orbitals
Energy (eV)
HOMO
PBE: PDOS plot for Cu
+
(dmbpy)2
PF6
-
N atoms
Ci1
Cu atom
C and H atoms
0.0
0.5
1.0
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
PBE: PDOS plot for Cu
2+
(dmbpy)2
2PF6
-
Cu atom
N atoms
Ci1
Ci2
C and H atoms
HUMO
HUMO
spin up channel
Energy (eV)
spin down channel
LUMO
Virtual Orbitals
Occupied Orbitals

DENSITY FUNCTIONAL THEORY Cu Electronic properties
PBE0: Cu PDOS analysis
Upon loading (Cu+
Cu2+
) reshaping of the peaks are observed
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
1.5
Occupied Orbital
Virtual Orbital HOMO-1
PBE0: PDOS plot for Cu
+
(dmbpy)2
PF6
-
Energy (eV)
N atoms
Cu atom
Ci1
C and H atoms
HOMO
0.0
0.5
1.0
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
Ci1
Ci2
Cu atom
N atoms
C and H atoms
LUMO
HOMO
HOMO
spin down channel
Energy (eV)
Occupied Orbitals
Virtual Orbitals
spin up channel
PBE0: PDOS plot for Cu
2+
(dmbpy)2
2PF6
-

DENSITY FUNCTIONAL THEORY Thermodynamic properties
Modeling the total reaction of the system
V0 potential includes solvated LiCi, and deposition of Li+
ion on the Anode
surface
V
M
= −
EUnloaded
nF
−
−ELoaded
nF
− V0

DENSITY FUNCTIONAL THEORY Mono-nuclear Voltages
Calculation of Relative Voltages
Ci-
Ci-
Ci-
Ci-
Ci-
VM
= – EUnloaded
– ELoaded
– V0
nℱ
Vrelative
= VM
– (VFe
)reference
= VM–Fe
Ci-
CiCi
PCM Model
Without counter-ions:
Way off by 1.5 V for Cu complex
PBE PBE0 Exp
VRu−Fe(V) +0.25 +0.31 +0.20
VCu−Fe(V) -2.51 -2.61 -1.03
With counter-ions:
VRu−Fe(V) VCu−Fe(V)
Ci ClO−
4 PF−
6 TFSI−
ClO−
4 PF−
6 TFSI−
PBE/PCM 0.17 0.28/0.24 0.31 -1.04 -0.68/-0.4 -0.85
PBE0/PCM 0.37 0.34/0.32 0.26 -0.97 -0.85/–0.5 -0.95
Exp 0.20 0.20 0.19 -1.03 -1.07 -1.14

Bi-nuclear
Bi-nuclear complex: Low dimensional system

Bi-nuclear Low dimensional system
Bi-nuclear: Low dimensional system
Experimentally, two compounds:
With one [a] and two [b] alkyl
chains are observed
Statistically, compound [a] is in
majority we decided to model this
system
N1 region N2 region
-(CH2
)n
-
d1 d2
dM
Ci
Ci
Our Approximation
[a]
[b]
-(CH2
)n
-
-(CH2
)n
-

Bi-nuclear Structural properties
Global geometry analysis
Exploring conformational space with alkyl chain of length n, − (CH2)n − ≡ nC
Interplay between cation center and counter-ions to find the optimum
geometry (Purely electrostatic interaction)

Bi-nuclear Local geometrical parameters
Local Geometry of Iron sites w.r.t chain length
Average bond distances for two sites with respect to chain length
6 C 4 C 2 C
1 . 9 5 0
1 . 9 5 5
1 . 9 6 0
1 . 9 6 5
1 . 9 7 0
X C : P B E S i t e F e 1
E x p
A l k y l c h a i n n C
Fe1-N1(Bonddistances)
F e 1 - N 1 : N
F e 1 - N 1 : F L
6 C 4 C 2 C
1 . 9 5 0
1 . 9 5 5
1 . 9 6 0
1 . 9 6 5
1 . 9 7 0
E x p
X C : P B E S i t e F e 2
A l k y l c h a i n n C
F e 2 - N 2 : N
F e 2 - N 2 : F L
Fe2-N2(Bonddistances)

PBE: Comparison of PDOS plot for FL (Full loaded) system
Ligand field effect preserved similar to Mono-nuclear PDOS
Bi-nuclear Mono-nuclear
- 2 0 - 1 9 - 1 8 - 1 7 - 1 6 - 1 5 - 1 4 - 1 3 - 1 2 - 1 1 - 1 0 - 9 - 8 - 7 - 6 - 5 - 4 - 3 - 2 - 1 0
0 . 0
0 . 5
1 . 0
1 . 5
- 2 0 - 1 9 - 1 8 - 1 7 - 1 6 - 1 5 - 1 4 - 1 3 - 1 2 - 1 1 - 1 0 - 9 - 8 - 7 - 6 - 5 - 4 - 3 - 2 - 1 0
0 . 0
0 . 5
1 . 0
1 . 5
F e 2 a t o m
N 2 a t o m s
C i 2
C i 3
C i 5
C a n d H a t o m s
6 C : F L
H O M O
E n e r g y ( e V )
H O M O
L U M O
O c u p i e d O r b i t a l s
V i r t u a l s O r b i t a l s
S p i n u p c h a n n e l
S p i n d o w n c h a n n e l
6 C : F L
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
1.5
2.0
0.0
0.5
1.0
1.5
2.0
HOMO
Spin up channel
Spin down channel
LUMO
HOMO
Energy (eV)
Fe atom
N atoms
Ci1
Ci2
Ci3
C and H atoms
PBE: PDOS plot for Full loaded Mono-Nuclear complex
Occupied Orbitals
Virtuals Orbitals
t2g
eg
∆o
=0.62 eV
Ci1
Ci2
Ci3

PBE0: Comparison of PDOS plot for FL (Full loaded)
system
Ligand field vanished similar to Mono-nuclear PDOS
We observe metal sites are quite independent
Bi-nuclear Mono-nuclear
- 2 0 - 1 9 - 1 8 - 1 7 - 1 6 - 1 5 - 1 4 - 1 3 - 1 2 - 1 1 - 1 0 - 9 - 8 - 7 - 6 - 5 - 4 - 3 - 2 - 1 0
0 . 0
0 . 5
1 . 0
- 2 0 - 1 9 - 1 8 - 1 7 - 1 6 - 1 5 - 1 4 - 1 3 - 1 2 - 1 1 - 1 0 - 9 - 8 - 7 - 6 - 5 - 4 - 3 - 2 - 1 0
0 . 0
0 . 5
1 . 0
F e 2 a t o m
N 2 a t o m s
C i 2
C i 3
C i 4
C a n d H a t o m s
6 C : F L
H O M O
E n e r g y ( e V )
H O M O L U M O
6 C : F L
O c c u p i e d O r b i t a l s
V i r t u a l O r b i t a l s
S p i n u p c h a n n e l
S p i n d o w n c h a n n e l
Ci1
Ci2
Ci3
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2
0.0
0.5
1.0
1.5
0.0
0.5
1.0
1.5
PBE0: DOS plot for Fe
3+
(dmbpy)3
3PF6
-
Mono-Nuclear complex
Occupied Orbitals
Virtual Orbitals
spin down channel
LUMOHOMO
Energy (eV)
spin up chanel
HOMO
Fe atom
Ci1
Ci2
Ci3
N atoms
C and H atoms

PDOS plot for HL (Half loaded) system
-(CH2
)n
-
dM
Ci
Ci
Fe1
FLN
Fe2
e-
e-
Ci
Ci
Ci
-20 -15 -10 -5 0
0.0
0.5
1.0
0.0
0.5
1.0
Occupied Orbitals
Virtual Orbitals
spin up channel
HOMO
spin down channel
HOMO
PBE0: HL Site 1
Energy (eV)
Fe1 atom
N1 atoms
C and H atoms
-20 -15 -10 -5 0
0.0
0.5
1.0
1.5
0.0
0.5
1.0
1.5
spin down channel
spin up channel
Occupied Orbitals
Virtual Orbitals HOMO
Energy (eV)
HOMO
PBE0: HL Site 2
Fe2 atom
N2 atoms
C and H atoms
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0
0.0
0.5
1.0
1.5
Energy (eV)
PBE: Schematic representation for N complex
Ef
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0
0.0
0.5
1.0
1.5
Energy (eV)
Ef
PBE: Schematic representation for FL system
e-
No tunneling effect observed for PBE functional

Bi-nuclear Bi-nuclear Voltages
Voltage comparison of Mono & Bi-nuclear complex
–(CH2
)n
– = nC
dM
FL=D3,3
N=D2,2
N=D
HL=D2,3
M1/2
= Fe1/2, Ru1/2
Dn1,n2
= [Fe1(dmbpy)3
] n1
Ci + nC + [Fe2(dmbpy)3
] n2
Ci
n1
+ n2
+
VHL
= – E D2,2
+ E0
– E D3,2
F
VFL
= – E D2,2
+ 2E0
– E D3,3
2F
2 . 8
3 . 0
3 . 2
3 . 4
3 . 6
3 . 8
4 . 0
4 . 2
4 . 4
H L
P B E : 2 C
P B E : 4 C
P B E : 6 C
V m o n o - n u c l e a r
≈ 4 . 2 0 5
F e B i - n u c l e a r c o m p l e x v o l t a g e : f o r C i = P F 6
-
Voltage(Vrel
)
P B E 0 : 2 C
P B E 0 : 4 C
P B E 0 : 6 C
F L
Fe PBE0 PBE
alkyl VHL VFL VHL VFL
2C 3.00 3.76 - 4.16
4C 3.91 4.09 - 4.10
6C 3.89 3.96 - 4.15

MOLECULAR DYNAMICS (MD)
Contents

MOLECULAR DYNAMICS (MD) Amber potential
Amber Potential model
V(rN ) = bonds kij (rij − r0)2 + angles kθ(θijk − θ0)2 +
ndihedrals
i
ni,max
n
1
2
Vi,n[1 + cos(nωi − γi,n)]+
atoms
i<j
Aij
r12
ij
−
Bij
r6
ij
+
qi qj
εij rij
r0
rij
Vbond
Vangle
θijk
θ0
Vdihedrals
Bonded Interactions
ω
Nonbonded Interactions
Vnonbond
= VvdW
+Velectroﬆatic
qi
qj

MOLECULAR DYNAMICS (MD) Development of the Potential
Parameterization of the Potential using Seminario method
V(rN ) = bonds kij (rij − r0)2 + angles ka(θijk − θ0)2 +
((((((((((((
ndihedrals
i
ni,max
n
1
2
Vi,n[1 + cos(nωi − γi,n)] + atoms
i<j
Aij
r12
ij
−
Bij
r6
ij
+
qi qj
εij rij
Parameters obtained from the first shell
ignoring dihedral term. Because the structure
is quite rigid
Å AT Exp DFT parm10 Gaff
Fe − N M1-Yi 1.965(3) 1.96 - -
C1 − C1 cp-cp 1.472(6) 1.470 1.400 1.485
N − C1 Yi-cp 1.350(0) 1.363 1.339 1.339
nCi-
nCi-
nCi-
nCi-
nCinCi
Ci=TFSI-
Parameterization of inner sphere
C1 C1’

MOLECULAR DYNAMICS (MD) Solvent model
Creation of Acetonitrile (ACN) Solvent box
Explicit Solvent Model created: ACN
0.121
-0.269-0.422 0.329
n1 c1 c3
hc
Parameters for ACN taken from GAFF database
RESP charges obtained at PBE:Def2SVP level of theory
At Equilibrium, achieved the density around ρ ≈ 0.77 g/cm3
at 300 K

MOLECULAR DYNAMICS (MD) Simulation procedure
Simulation procedure
General steps for MD Simulation
Polymer
construction
Solution construction
solvents molecules randomly inserted
Minimization of the structure
NVT → Equilibration (NPT) → Dynamics (NVE)
ACN
Solvent

MOLECULAR DYNAMICS (MD) Validation of Potential
Validation of Potential on Bi-nuclear system
Validated 6C chain for N and FL compound
MD DFT
Å N FL N FL
M1-nb 2.0 ± 0.04 2.0 ± 0.03 1.965(3) 1.96(3)
cp-cp 1.50 ± 0.02 1.50 ± 0.03 1.472(6) 1.473(6)
nb-cp 1.35 ± 0.01 1.35 ± 0.02 1.350(0) 1.350(0)
Deff (10−5cm2/s) 0.652 0.525 - -
Influence of the solvent (ACN) on the structure and diffusivity of Ci

MOLECULAR DYNAMICS (MD) Validation of Potential
Visualization of MD Trajectories for Bi-nuclear
Without Solvent With Solvent

CONSTRUCTION OF MACROMOLECULE
Construction of Poly-nuclear complex
Developed Fe Poly-nuclear complex using
in-house python code
With varying chain size, 4C and 6C, Cavity
Region (CR) is expanded
Boundary regions fixed with Methyl group

CONSTRUCTION OF MACROMOLECULE Fixing RESP charge
Fixing RESP charge on the main unit
Effective charge fitted according to this equation
α × Q
Alkyl Chain
2 + Q
(bpy)3
+ Q
Fen+
+ Q
n(TFSI−)
+ β × Q
n(CH3)
= 0
......
...
...
...
...

MD SIMULATION RESULTS OF POLY-NUCLEAR COMPLEX
Selection of Complex size
Poly-nuclear size Deff (10−5
cm2
/s) ρ (g/cm3
) β (t) = d log MSD
d log t
5606 0.10 0.82 0.59
10847 0.091 0.84 0.55
18133 0.085 0.86 0.53
Large structure means more statistics
Mean square displacement (MSD) plot for three complex size (Slopes are almost
same)

MD SIMULATION RESULTS OF POLY-NUCLEAR COMPLEX
Visualization of MD Trajectories for Poly-nuclear complex
Solvation stabilizes the structure due to screening effect (1 ns simulation)
With SolventWithout Solvent

MD SIMULATION RESULTS OF POLY-NUCLEAR COMPLEX Effect of Cavity on the Diffusivity of Ci
Effect of Chain Length on the Diffusivity of Ci
Effective diffusion (Deff ) of Ci in 4C chain is
lower than 6C due to crowded environment
large CR region allows more accumulation of
Li+
/Na+
ions
With respect to Bi-nuclear Deff reduce by a
factor of ≈ 10 due to entrapment
Å N FL
Fe − N 2.0 ± 0.02 2.0 ± 0.04
C1 − C1 1.50 ± 0.02 1.50 ± 0.03
N − C1 1.35 ± 0.01 1.35 ± 0.02
4C 6C 4C 6C
Deff (10−5
cm2
/s) 0.047 0.091 0.029 0.077
0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0
0
5
1 0
1 5
2 0
2 5
3 0
3 5
4 0
4 5
t ( p s )
<MSD>Å
2
4 C N e u t r a l
6 C N e u t r a l
4 C F u l l l o a d e d
6 C F u l l l o a d e d
3 0 0 3 5 0 4 0 0 4 5 0 5 0 0
0 . 5 5
0 . 6 0
0 . 6 5
0 . 7 0
0 . 7 5
0 . 8 0
0 . 8 5
0 . 9 0
T ( K )
ؒ(g/cm
3
)
4 C : F L
6 C : F L

MD SIMULATION RESULTS OF POLY-NUCLEAR COMPLEX Temperature Effect
Effect of Temperature on the Diffusivity of Ci
Simulated diffusion constant almost follows the Arrhenius function
(D = Ae
−Ea/RT
) with an activation energy (Ea) estimated: 18.652 kJ/mol.
Compared to [TFSI]
−
[BMIm]
+
ionic liquid, the experimental activation energy
is 27.50 kJ/mol
0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0
0
4 0
8 0
1 2 0
1 6 0
2 0 0
2 4 0
2 8 0
3 2 0
t ( p s )
<MSD>(Å2
)
6 C : F L T = 3 0 0 K
6 C : F L T = 3 5 0 K
6 C : F L T = 3 7 5 K
6 C : F L T = 4 0 0 K
6 C : F L T = 5 0 0 K
0 . 0 0 1 8 0 . 0 0 2 1 0 . 0 0 2 4 0 . 0 0 2 7 0 . 0 0 3 0 0 . 0 0 3 3
- 5 . 5
- 5 . 0
- 4 . 5
- 4 . 0
- 3 . 5
- 3 . 0
- 2 . 5
6 C : F L
ln(D(m
2
/s))
T
- 1
( K
- 1
)

CONSTRUCTION OF TRANSIENT STATE
Initiation of the loading process in a N state
Description of the Transient state
FL units embedded in a N complex
Counter-ions randomly inserted into the cavity region to study the diffusivity
N
N
N
N
N
N
FL
FL
FL
FL
FL
FL
FL

CONSTRUCTION OF TRANSIENT STATE Diffusion of Ci in Transient state
Diffusion of Ci in Transient state
For certain time frame we define the motion as Walking confined diffusion
Deff obtained 0.09 ×10−5
cm2
/s
5 0 0 1 0 0 0 1 5 0 0 2 0 0 0 2 5 0 0
2 0
4 0
6 0
8 0
1 0 0
1 2 0
1 4 0
1 6 0
1 8 0
2 0 0
t ( p s )
<MSD>Å
2
O v e r a l l d i s p l a c e m e n t R
2
O v e r a l l d i s p l a c e m e n t X
2
O v e r a l l d i s p l a c e m e n t Y
2
O v e r a l l d i s p l a c e m e n t Z
2
6 C c h a i n : D i f f u s i o n o f T F S I
-
i n a F L s t a t e

Conclusions
Conclusions
Theoretical approach
PBE0 tends to delocalize
PBE0 is the least adequate approximation for these systems (Fe, Ru and Cu) in
terms of three properties (Geometry, Electronic & Voltage)
Results
Mono-nuclears voltage closely agrees with the experimental results
No effect of longer chains on the voltage is observed
Cu complex shows large conformational change upon loading making it less
reliable to use as cathode material
MD Simulation
Large cavity regions is preferred for fast diffusion hence, quick charging
There is influence of crowded porous environment on the diffusion of Ci

Perspectives
Perspectives
In reality, there will be alkyl chains
missing and the diffusion is expected
to change.
Study of the stabilization effects for
Cu complex with different ligands

First principle and Atomistic simulation of transition metal compounds for battery application

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