E
Energy
Storage:
St
Materials
M t i l for
f Safe
S f Li-Ion
Li I Batteries
B tt i
Karim Zaghib
Energy Storage and Conversion SCE
February 2010
Hydro-Québec has been
involved with electrochemical
energy
gy storage
g since 1970.
2
Primary Energy Sources on Earth
Energy Storage Methods
1.
Carbon storage
(C, CHx, CHOx…)
3
2.
Electrochemical
storage
(Li H2, redox…)
(Li,
d
)
3.
Physical storage
(kinetic energy,
potential…)
t ti l )
Carbon Storage
Advantages
 Immediate
I
di t availability
il bilit ((coal,
l oil,
il gas))
 High energy density and power
density (Wh, W/kg, W/L)
 Partially renewable (biomass)
Drawbacks
 Slow to renew
• Oil (> 100 million years)
• Biomass
Bi
(3 months
th tto 25 years))
 Inefficient conversion to electricity
( 30%)
 Pollution and GHG emissions
4
Electrochemical Storage: Batteries
Considered the most noble
form of energy, electricity is
flexible, efficient and clean,
but it is instantaneous and
relies on an ever
ever-present
present
source.
Battery storage of electricity
made it possible to
 Develop intermittent sources of
renewable energy (photovoltaic
and wind power)
 Provide an alternative to fossil
fuels in the transportation sector
( 27% of the energy budget)
5
Progress in Storage Batteries
Baghdad battery
Volta
1800 Zn-Cu
Leclanché and
alkaline cells
1866 Zn
Zn-MnO
MnO2
Ni-MH
Ni
MH 1990
Toyota 1997
Ni-Cd 1900
Bioelectrogenesis
G l
Galvani,
1780
80
Fe-Cu
6
Lead-acid
ead ac d
Planté, 1859
Pb-PbO2
Li-ion
Sony, 1991
Ideal Battery
High-performance reagents
 Powerful reducing agent
 Strong oxidizing agent
Rapid, reversible
reactions
ti
 Insertion material allowing
several thousand cycles
 Small ionic radius, stable structure
Stable conductive electrolyte
 Redox couple with a wide stability range
 Dissociating solvent and conductive salt
Light,
g , non-toxic materials
 Abundant and cheap
 Easy to use
Safe anode-cathode-electrolyte combination
7
Lithium-Metal-Polymer vs. Lithium-Ion Technology
Lithium-metal-polymer
M t lli lithi
Metallic
lithium
Solid polymer
Hydro-Québec–Avestor
1985 1999
1985–1999
Bolloré – 1999–2010
LiV3O8
LiFePO4
60°C to 80°C
Insulator
Lithium film
(anode)
Electrolyte
Cathode
8
100 
Metallized film (current collector)
Li-ion
Anode
Carbon
Electrolyte
Liquid electrolyte:
1M LiPF6 + C + DEC
Cathode
Operating
temperature
LiCoO2
Sony – 1991
–20°C to 60°C
Existing Technological Barriers
Cost
 Materials amount to 60% of battery cost
 Cost pushed up by strong demand for
metals in China
Safety
 Costly recalls like those of small Sony
batteries (> $600 million)
 Recalls likely to become more frequent
Energy density (transportation
sector)
 Effort
optimum
range–size
Eff t to
t achieve
hi
ti
i
ratio
Charging time
Service life
 Number of cycles
9
Chicago Tribune (July 2006)
Technologies Developed at Hydro-Québec
Hydro Québec
10
Battery Materials: Safety, Cyclability and Power
11
Cathode: Olivine Structure
Properties
Thermal stability of LiFePO4
and FePO4 phases: 400ºC
Low-cost material
Environmentally friendly
High theoretical capacity
Low electronic conductivity
Low density
LiFePO4
12
Carbon coating patented by
HQ-UDM (1998)
Cathode: Strategy to Offset Low Electronic Conductivity of LiFePO4
Uniform carbon coating
Nanostructuring a
low-cost electronic
conductor
Particles
P
ti l
coated with
carbon
13
Initial energy density:
100–110 mAh/g
Energy density with carbon:
150–165 mAh/g
Cathode: Advantages of LiFePO4 – Safe, Cost-Effective and High Power Density
Battery
LiFePO4
LiCoO2
LiMn2O4
Li(NiCo)O2
Optimal
Unstable
Acceptable
Unstable
Very
environmentally
y
friendly
Very
y dangerous
g
Environmentally
friendly
Very
dangerous
Superior/
Excellent
Acceptable
Insufficient
Acceptable
Energy density
(Wh/kg)
110
150
120
185
Power density
(W/kg)
3,000
1,350
950
1,400
Long-term costeffectiveness
ff ti
Superior/
E
Excellent
ll t
High
Acceptable
High
Operating
temperature
te
pe atu e
Excellent
Deteriorates
outside –20°C to
55°C
Deteriorates
quickly
q
y above 50°C
–20°C to
55°C
Safety
Environmental
risk
Cyclability
14
((–20°C
20 C to 70°C)
70 C)
Cathode: Safety of LiFePO4
15
Cathode: Safety of LiFePO4
16
Electrolyte: Advantages of Ionic Liquid
Conventional electrolyte
Ionic liquid
Flammable
Non-flammable
In situ SEM imaging
Conventional electrolyte:
1M LiPF6 + EC + DEC
Ionic liquid (molten salts):
EMI FSI and EMI
EMI-FSI
EMI-TFSI
TFSI
High vapor
pressure
17
Zero vapor
pressure
Conventional electrolyte compared to ionic liquid
Anode: Spherical Natural Graphite
Jet milling
Natural graphite
Mechanical fusion
Purification
372 mAh/g
1
09
0.9
Advantages:
Easy application
Compacting
density
Porosity
Diffusion
Lower cost
X in LiXC6
0.8
0
0.7
0.6
0.5
0.4
0.3
0.2
0
18
50
100
150
I (mA/g)
200
250
++
––
++
Anode: Li4Ti5O12
Potentia
al (V)
Advantages:
High cyclability
High-rate charging
Stable structure (zero expansion)
No temperature rise
Oxygen Titanium
19
Lithium
1.5 V vs. Lithium
Low cost and high
g safety
y
Li4Ti5O12/ LiFePO4: Operating
voltage of 2 V (double Ni-MH
or Ni-Cd)
Li4Ti5O12
Time (h)
Anode: Zero Expansion Due to Titanate
FeS: Expanding material
Titanate: Zero-expansion material
Source: Materials characterization laboratory
20
LTO-LFP: Electrochemical Properties
Very stable output for
an 18650 cell
Nearly 20,000 cycles
Nearly 30,000 cycles
Charge to 12C (5 minutes)
Charge to 15C (4 minutes)
Discharge to 5C (12 minutes)
Discharge to 5C (12 minutes)
At a rate of one cycle per day,
the battery should last more than 50 years.
21
Hydro-Québec Licensed Technology
Cathode
LiFePO4

Canada
Phostech

Japan
Sony
Electrolyte
Ionic liquids
 Japan
DKS
Nippon Shokobai
Nippon Catalyst
Elexcells
 Europe
BASF
Merck
Solvent Inc.
Solvionic
Anode
Graphite
 Brazil
Nacional de Grafite
 Canada
Industrial Minerals
C-Li4Ti5O12
 Europe
Süd Ch i
Süd-Chemie
 U.S.
Innanovation
 Asia
Phet
22
LiFePO4: Applications
www.phet.com.tw
23
5-Minute Electric Vehicle Charging (IREQ, September 17, 2010)
24
24
Energy Density (Wh/kg) and Power Density (W/Kg)
HEV – Hybrid electric vehicle (electric + internal combustion)
PHEV – Plug-in hybrid electric
Ene
ergy denssity (Wh/kkg)
Range
1,000
Internal
ICcombustion
engine
6
4
engine
PHEV target
Li -ion
100
6
4
Fuel cells
100 h
2
Ni -MH
Pb-acid
Pb
acid Acid
Lead
Lead-Acid
2
HEV target
10 h
10
Capacitors
6
4
2
1h
1
0
10
0.1 h
10
Acceleration
1
36 s
10
2
3
10
5-V technology:
Oxide-olivine
Hydro-Québec has the materials needed
to achieve the desired power and range
4
10
P
Power
density
d
it (W/k
(W/kg))
Existing technology:
LiFePO4/Graphite
p
25
3.6 s
Energy Density: HV Olivine-Based Cathodes
5.0
LiM nC oO 4 →
LiN iV O 4 →
LiM nC
C rO
O4 →
LiM n 1. 5N i0.5O 4 →
4.5
LiCoPO4 (Kyushu
↓University)
y)
↑
LiCoPO4 (theoretical)
Volta
age (V)
1,000 mW h/g
LiC oO 2 →
LiM n 2 O 4 →
4.0
LiC oV O 4 →
LiF ePO 4 (HQ + UT, SO NY )
↓
LiFePO4 (NTT, Kyushu University)
3.5
↓
LiFePO4 (theoretical)
700 W h/g
100 W h/g
2.5
0
50
300 W h/g
200 W h/g
100
400 W h/g
150
Energy density (mAh/g)
Performance of a few high-voltage cathodes
26
800 W h/g
↑
Olivine
Normal spinel
Inverse spinel
Stratified halite
3.0
900 m W h/g
LiN iO 2 →
500 W h/g
200
600 W h/g
250
Jet Propulsion Lab (JPL): NASA–Hydro-Québec Partnership
The Li-ion
Li ion battery with
Hydro-Québec's multilayer
LiFePO4 anode will be
onboard the ATHLETE
robot.
JPL will develop a lowtemperature electrolyte
(−10°C
(−10
C to −65
−65°C)
C).
27
LiMnAlO2
or
Li[LiNiMn]O2
Current
collector (Al)
LiFePO4
Source: ECS (Washington, October 2007)
Targets
Medium-term battery: > 75 kWh
Range of 480 km: > 315 Wh/kg or 780 Wh/L per cell
Average car weight (Toyota Camry)
=1
1,500
500 kg
Engine weight + Full fuel tank
 400 kg ( battery weight)
Capacity required for range of 480 km
= 75 kWh (based on 6
6.4
4 km/kWh)
Battery energy density (mass)
= 75,000/400 = 188 Wh/kg
B tt
Battery
energy density
d
it (volume)
( l
)
= 188 x 2.5
2 5 = 470 Wh/L
Energy density per Li-ion cell (mass)
= 188/0.6 = 313 Wh/kg
E
Energy
d
density
it per Li
Li-ion
i cellll ((volume)
l
)
= 313 x 2.5
2 5 = 783 Wh/L
Specific energy of present Li
Li-ion
ion batteries = 100 Wh/kg
28
Energy Density Leaders
M
Reaction
(kJ/mol)
(kJ/mol)
Energy
(Wh/kg)
Li
2 Li + 1/2 O2  Li2O
–561.9
–598.5
11,246
Li2O2
Catalyst
Carbon
Lithium
metal
anode
(–ve)
Li i
Li-ion
Electrolyte
Porous composite electrode cathode (+ve)
TNT
Sulphide
Methanol
Ethanol
Lithium
Lithi
Gasoline
0
29
3,000
6,000
9,000
12,000
15,000
Li-Air Cell with Non-Aqueous Electrolyte
Interface layer
GDE
Precipitation of Li2O2 on the catalyst or
membrane: Polarization
Lithiium
Li+
Li2O2
Porous reservoir
Catalyzed carbon
PTFE (Teflon)
Solid electrolyte
30
Polyphase boundary
Liquid (solvent), solid (electrocatalyst)
and
d gaseous (O2) states
t t
Non-uniform precipitation of Li2O2:
Inadequate cathode performance
Uniform precipitation of Li2O2 in the
reservoir: Optimal performance
O2 + e− = O2−+ e− = O22− electron transfer at the boundary
2 Li+ + O22− = Li2O2 (s) solid precipitate in the reservoir
V2G*: Two-Way Energy Flow
The vehicle can both receive energy from and supply
energy to the grid on demand.
*V
Vehicle-to-grid
hi l t
id
Safe, efficient batteries mayy have positive
p
impacts
p
on the
power grid.
31
Principle of Vehicle-to-Grid (V2G) Interface
Plugged in electric vehicles form a distributed source of
energy.
The arrows show the direction of energy flow.
32
Basic V2G Statistics
Average time driven: 2 h/day
A
Average
time
ti
parked:
k d 22 h/d
h/day
Average distance driven: 50 km/day
Average vehicle power output: 10 to 20 kW
Total capacity of U.S. power plants: 811 GW
U.S. automobile fleet: 176 million vehicles,
thus a potential capacity of 2,640 GW
In Québec:
 Capacity the Hydro-Québec system: 35 GW
 Potential capacity of the automobile fleet (4 million light
vehicles): 60 GW
33
V2G Applications
Peak demand
Management
g
of transient loads
Voltage control
Frequency regulation
Power quality
Energy storage
Payoff
P
ff for
f a participating
ti i ti
V2G car owner
(data for mid-sized cars over 10 years)
Peak power
Spinning reserve
Control service
$267
(510 − 243)
$720
(775 − 55)
$3,162
(4 479 − 1,317)
(4,479
1 317)
Source: California Air Resources Board (CARB), Feasibility of Electric Drive Vehicles as Distributed Power
Generation Assets in California,, June 2001.
34
Conclusions
Battery technology is booming.
A new generation is preparing to replace Li-Co.
China is a step ahead with LiFePO4.
High-rate charging will mark a shift in how public
charging systems are viewed.
g cyclability
y
y ((> 25,000
,
y
) will improve
p
High
cycles)
the EV
cost-benefit ratio and boost penetration.
V2G may ultimately also catalyze EV penetration
penetration.
35