Roles of Modeling and Simulation in xEV Battery Revolution
Chao-Yang Wang
The Pennsylvania State University
University Park, PA 16802
ecec.mne.psu.edu
EC Power
State College, PA 16803
www.ecpowergroup.com
• Background
• Elements of Battery Modeling and Simulation
• Applications
• Summary and Outlook
Outline
Electrochemical Engine Center
(founded in 1997)
Recently renovated and facilities
upgraded with $25M
• Global competitions
• Large number vehicle models; customized systems
• Faster – traditional processes of physical build, test, system
integrate & refine are too slow to be practical
• Cheaper
• Better
• Big Data driven – unavailable life testing data over 10-20 years
• Battery safety cannot rely solely on destructive testing
xEV Battery Development Challenges
A Pathway to Reduce Cost: CAE-led Development
Vehicle crash-worthiness through simulations
1960 2000+Destructive-testing only
approach; no simulation
method existed
Industrywide adoption.
CAE-led development
with >80% reduction in
testing
Computer-aided engineering enables getting a product right
the first time and eliminate very costly issues later on
Our Process of CAE-led Battery Development
“Walk the Talk”
Battery Modeling & Simulation through e.g. GT-AutoLion
• Software suite for total battery engineering:
performance, life and safety; only industrial
project recognized by 1st and 2nd DOE CAEBAT
programs
• Fast, robust & accurate tool for real Li-ion
battery geometries
• Aid OEMs/battery developers to accelerate
product development of low-cost, safe, long-
lasting Li-ion batteries for xEVs
Materials Characterization
Set Gold Standard for xEV Battery Engineering
Physico-chemical Modeling
Computational Algorithms
Diagnostics & Validation
Performance Life Safety
2.42
2.22
2.02
1.83
1.63
1.43
1.23
1.03
0.84
0.64
0.44
He
ig
ht
(cm
)
0
2
4
6
8
10
Length (cm)
0 50 100 150 200 250 300 350 400 450
Discharge Capacity (Ah)
Ce
llV
olta
ge
(V)
0 0.2 0.4 0.6 0.8 1 1.2 1.43
3.2
3.4
3.6
3.8
4
4.2
4.4
01000200030005000
Data, Cycled Number
1C discharge
Solid Line: Model Simulation
• highest active material utilization• highest energy density (Wh/kg)• lowest cost $/kWh
• longest life• lowest life-cycle cost
• safest systems by virtual & actual testing
What is in GT-AutoLion?
Battery Materials Database
Cathode materials:
• NCM111,523, 622, 811
• LFP
• LMO
• LCO• NCA
Anode Materials:
• Graphite
• LTO
• Hard Carbon
• Si/C
• Li metal
1,000,000Coin cells built and tested to
acquire temperature/concentration
dependent properties
12Built-in cell chemistries
that can be instantly
created and simulated.
All AutoLionTM softwares come equipped
with the material data built-in, which offers
the following benefits:
• Instant access to all 12 cell chemistries:
new cells can be designed in a matter of
minutes
• High quality data at various
concentrations and temperatures
• Users have freedom to input their own
properties as a function of temperature
and SOC through user defined functions
Li+
negative electrode positive electrodeseparator
4M
0.1M
1M
Ele
ctro
lyte
Conce
ntr
atio
nElectrolyte distribution in
a Li-ion cell under
discharge
Data collected for electrolyte concentrations
ranging from 4M to 0.1M
-30°C 60°C
Users can add any new material to the software thru UDF.
Electrolytes:
• LiPF6
• PEO polymer
• LIPON/oxides
• Sulfide electrolyte
9
Coin cells under testing
Rate performance @ RT
Capacity test @ RT
Si-Gr/NMC811 full coin cell
0 50 100 150 200 2502.5
3.0
3.5
4.0
4.5
5.0
NMC811 loading: 21.59 mg/cm2
1st cycle, efficiency: 91.05%
2nd
cycle, efficiency: 99.42%
Room temperatureC/10 charge/discharge
Coin cell: Li/NMC811
Voltag
e (V
)
Capacity (mAh/g)
0 50 100 150 200 2502.5
3.0
3.5
4.0
4.5
5.0
C/10 C/3 1C
Coin cell: Li/NMC811
NMC811 loading: 21.59 mg/cm2
Voltag
e (V
)
Capacity (mAh/g NMC)
0 50 100 150 200 2502.5
3.0
3.5
4.0
4.5
5.0
C/10 charge/discharge4.35-2.7 V
1st cycle
2nd
cycle
Room temperature
Coin cell: SiO-Gr/NMC811
Voltag
e (V
)
Capacity (mAh/g)
0 100 200 300 400 500 600 70020
25
30
35
40
90
92
94
96
98
100
Eff
icie
ncy
(%)
Capacity
(Ah)
Cycle number
Capacity
4.35V-2.7V @ 0.75C/0.75C
Cathode: NCM811Anode: SiO/Graphite
Energy density 260 Wh/kg
Efficiency
0 100 200 300 400 500 600 70060
70
80
90
100
90
92
94
96
98
100
Eff
icie
ncy
(%)
Capacity
rete
ntion (%
)
Cycle number
Capacity retention
Cathode: NCM811Anode: SiO/Graphite
Energy density 260 Wh/kg
4.35V-2.7V @ 0.75C/0.75C
Efficiency
Cycle test of a pouch cell
LiNi0.8Mn0.1Co0.1O2 (NMC811): Cathode Material for EVs in 2022
3-Yr, $1.95M DOE Project for Highly Stable NMC811 or 9055
• Need high-capacity cathode material with better safety and higher cycle/calendar life,
requiring much better stability
• NMC811 surface-coated by LixMyPO4 (LMP, M=Fe, Mg, Al, Ti or their combinations)
Cycling stability of an LFP-coated
NCM811/Graphite 2.5Ah pouch cell
cycled with 1C/1C at RT and 40oC.
SEM images of (a) original and (b) LFP-coated
NCM811 particles. (c, d) EDS elemental (P and
Co) mapping image of LFP-NCM811 particle.
XRD spectra of LFP-
NCM811 and NCM811.
Can We Trust GT-AutoLion?
Capacity (mAh)
Vo
lta
ge
(V)
Te
mp
era
ture
Inc
rea
se
(°C
)
0 500 1000 1500 2000 25002
2.5
3
3.5
4
0
20
40
60
1C (2.2A) DischargeModel
Experimental data
45°C
25°C0°C
-10°C
-20°C
2.2 Ah NMC/Graphite 18650 cell Dynamic pulse demand simulation at 0oC
for 1.2Ah NMC/C cell
Cycle life simulation for LFP/C cell External short of 1.6 Ah NMC/C cell
Case Study 1: All-Climate Battery (ACB)
• ACB: Anode + Cathode + Electrolyte + 4th Component: a µm-thin Ni foil for rapid self-
heating; 2-3oC/sec
• Self-heat in 5-15 seconds & consumes 1-3% battery energy for 20-30oC temp rise
Wang et al., Nature, 529 (2016) 515-518.
13
• Self-heating time: 12.5 sec
• (energy) capacity consumed:
2.9% of 10Ah
Self-Heating from -20oC
Highest Energy Efficiency in Real World Driving
14
ACB realized 80% of room-temperature cruise range at -30oC with present-day LiB, and
achieve 92% of RT cruise range with 300 Wh/kg LiB.
All-Climate Range (ACR) – the cruise range guaranteed in -20oC to 40oC vs. RT range
All
-Cli
mat
e R
ang
e (%
)
100
0
Zhang et al., J Power Sources, 371 (2017) 35-40.
Temperature-Independent Battery
15
2C, 3-sec disch. pulse @100%SOC
NCM523/Gr cell, 33Ah, 200 Wh/kg
Internal Resistance – DCR
(-20oC, 100% SOC) (10oC, 97%SOC)10 sec
16
Commercial Applications
• Automakers and battery manufacturers around the
world have licensed ACB technology.
• 2022 Winter Olympic Games adopted ACB for all
10,000 electric vehicles; 4 types of cars and buses are
undergoing real-world testing this winter.
>260 km range @ -30oC outdoor; no heated garage
15-60 min fast charge stations
Hill climbing @-30oC
Regeneration downhill @ -30oC
BAIC EU260 Car, Yutong Luxury Van, & Foton 12m Bus at
HaiLaer Winter Vehicle Testing Center in March 2018Testing Conditions:
• All vehicles soaked in -40oC environment
for 72 hours (no plug-in for keeping
temperature)
• In 10 min, EVs drive away like normal
vehicles (0-100 km/h acceleration, regen,
fast charging…)
SUCCESS: All 3 types of vehicles powered by MGL’s ACB batteries PASSED!!!
Courtesy: the Winter Olympic Project of testing ACB technology in vehicles was planned and led by Prof. Sun Fengchun of BIT with
active participation from BAIC, Yutong, Foton & MGL
In-Vehicle Testing of All Climate Battery
Impact of ACB on EV Market in China (60% of the World)
EV markets in thesouth & east
ACB enables EVs in Cold and High-Altitude Regions
Source: China Electric Vehicle Monitoring Platform, Industry & Information Ministry/Beijing Institute of Technology,
Courtesy per Academician Prof. Sun FengChun.
Case Study 2: Fast Charging Battery (FCB)
Fast and Healthy Charging Anywhere, Anytime
Baseline, 0oC
10 Ah PHEV cell, graphite anode, NMC622 cathode; 175Wh/kg
FCB
• Simulations on evolutions of Li
deposition potential (LDP) in AL1D can
reveal max charge rate under certain
temperature before Li plating occurs, i.e.
LDP<0V.
• Energy-dense, thicker-electrode cells
need to operate at elevated temperature in
order to avoid Li plating upon fast
charging.
• AutoLion has been an instrumental tool
in discovering and designing ubiquitous
FCBs.
Maximum Charge Rates @ Various Temperatures
Guaranteed 15-min Charging at All Temperatures
Yang et al., PNAS
(2018).
Case Study 3: Energy-Dense EV Battery with High Safety/Longevity
• If using stable active materials/electrolyte and operated under Li plating-free
condition, high-energy EV batteries (220-240 Wh/kg) could be much safer and have
3000-4000 cycles.
• This translates to >600-800k miles, or the battery can last for 50 yrs
• Uber-durable batteries should be put in multi-life reuse, increasing usage value or
equivalently cutting down battery cost for each application and/or increasing ROI.
Gen 2 EV cell 220 Wh/kg,
1C/1C cycling
Summary and Outlook
Simulation-based development of Li-ion batteries for performance, life,
safety and cost is feasible and indispensable
Along with carefully established material database, efficient numerical
algorithms, and extensive experimental validation, CAE tools will play a
major role in developing xEV battery products faster, cheaper and better.
We did not invent Li-ion battery, but we can reinvent it every day using
model-based simulation tools.
Integrated with powertrain and vehicle simulators such as GT-SUITE,
possibilities to develop innovative and energy-efficient xEVs are endless.