2nd SINO
SINO--BRITISH Workshop
Investigation and Application of Redox Flow
B tt
Battery
ffor E
Energy St
Storage
Huamin Zhang
Chief Scientist of RFB Program of China
Prof. Dalian Institute of Chemical Physics (DICP CAS)
CTO. Dalian Rongke Power Co., Ltd.
Contents
¾ Challenges
g for VRB Commercialization
¾ Progress on Key Materials
¾ A PV
PV--VRB System for Telecom Station
¾ Large
L
Scale
S l VRB System
S t
Integration
I t
ti
About My Group
Huamin Zhang
Prof.: Dalian Institute of Chemical Physics
y
((DICP),
),
Chinese Academy of Sciences
Vice President and CTO: Dalian Rongke Power Co., Ltd.
National Chief Scientist of RFB Program
Research field
fields
s in my
yg
group
p in DICP
¾ Redox Flow Battery
¾ Proton Exchange Membrane Fuel Cell
¾ Regenerative Fuel Cell
¾ High Energy Density Battery
Advantages of RFB concluded as follows
¾ Independent system design for
Increase
power
power and capacity
Output Power Range: kWkW-MW;
Energy Storage Capacity : kWhkWh-10MWh
M
Module
¾ Long lifetime
Electroly
E
yte
¾ High efficiency (>75%)
¾ Deep discharge ability
¾ Low selfself-discharge, fast response
¾ Environmental friendly
y
¾ Operation safety
Increase
Capacity
Durability and Reliability Test
(From Jul. 2007)
U tto taday.,
Up
t d
lif ti
lifetime
test
t t off a 2 kW VRB system
t
has
h
been carried out over 1419 days (over 34060 hours,
hours, 9933
charge--discharge cycles ).
charge
Challenges of VRB for Commercialization
¾ poor electrolyte stability and less solubility lead
to lower energy density
¾ Low selectivity
y to the vanadium ions for ion exchange
g
membrane lead to the Unbalance of vanadium ions
and water , and the capacity degradation after long
operation time
¾ Low rated operation current density lead to high
material cost
¾ High cost of the ion exchange membrane
Limited the RFB practicability seriously
Contents
¾ Challenges
g for VRB Commercialization
¾ Progress on VRB Key Materials
¾ A PV
PV--VRB System for Telecom Station
¾ Large
L
Scale
S l VRB System
S t
Integration
I t
ti
Ion exchange membrane for VRB
Ion exchange membrane is employed to transport proton
and prevent cross mixing of positive and negative electrolytes.
The ideal membrane for VRB application
pp
¾ low permeability of vanadium ions
¾ High proton conductivity
¾ Good chemical stability
¾ low cost
Nafion® Membrane for VRB
CF2
CF2
n
CF
Membrane Function:
CF2
O CF2-CF-O
m
CF2CF2SO3H
CF3
¾Separate electrolyte
(
(vanadium
di
ions)
i
)
¾Transport proton
High Cost !!!
Low Ions Selectivity !!!
Our Research focused on:
¾ A Nanofiltration (NF) Membranes
¾ A Non-Fluoride Membrane
Nanofiltration (NF) Membranes for VRB
Principles
¾the stokes radius of vanadium ions
is much larger than that of H+
¾the charge
g density
y of vanadium ions
(V(IV),V(II), V(III)) is much higher than
protons
NF membrane fabrication
¾NF membrane prepared by phase
inversion method
¾Pore size distribution of membranes
can be controlled
Cost is much lower than Nafion
DICP NonNon-fluoride Membranes for VRB
Lifetime Test of NonNon-Fluoride Membranes
Performance of single cell with DICP Non-fluoride membrane
( d 80 mA/cm
(under
A/ 2)
The performance kept stable after running more
than 12 months
months. The battery has finished more
than 10000 cycles.
Lifetime Test of Non
Non--Fluoride Membranes
500W battery module with DICP Non-fluoride membrane (under 80 mA/cm2)
DICP NonNon-fluoride
Membrane
Nafion 115
membrane
CE
99.5%
95%
VE
80%
85%
EE
80%
80%
¾ Low Cost !
¾ Lower VE due to the
higher ohmic resistance
Two Generation NonNon-Fluoride
M b
Membrane
C
CE
VE
EE
DICP--1
DICP
99.5%
80%
80%
DICP--2
DICP
99%
8 %
85%
84%
VE is improved by
increasing The
membrane
conductivity
Stack Modules with Non
Non--Fluoride
Membranes for VRB
2 kW
1 kW
500 W
100 W
5W
Electrolyte Production
Vanadium Electrolyte Production Line
¾Bolong New Material Co.
High quality vanadium supplier
¾Yield --- 300 MWh/year
Carbon Plastic Bipolar Plate
1.0 m
Bulk resistance
< 0.17 Ω.cm
Bending strength
>28 MPa
Corrosion resistance
<0.7 uA.cm-2
Thickness
1 mm
Cost
<100 RMB/m2
Yield
10,000 m2/year
Carbon/plastic plates showed similar properties with commercial graphite
plates, while the cost almost the 1/10 of the graphite plates. It has been used
in stacks for demonstration widely.
Latest Progress on Key Materials and
Components of VRB in
i My
M group
Electric Control
Components
Sealing
g
VRB
System
Bipolar
Plate
Electrode
Ion Exchange
g
Membrane
Electrolyte
Stack
Module
Contents
¾ Challenges
g for VRB Commercialization
¾ Progress on Key Materials
¾ A PV
PV--VRB System for Telecom Station
¾ Large
L
Scale
S l VRB System
S t
Integration
I t
ti
Circuit Diagram for an offoff-grid PVPV-VRB
S t
System
F
For telecom
t l
station
t ti
Telecom
Station Load
PV Panels
PV Controller
Distribution
Cabinet
VRB St
Storage
220V AC
from Grid
(Diesel Generator Simulation)
Specification
Parameters
PV
6 kW
VRB System
2.4 kW / 54 kWh
Back up 72h
Load
500 W
Voltage Class
48V DC
VRB System
y
Design
g
¾ Bipolar plate, electrode,
membrane and electrolyte
are all homehome-made.
¾ Monitor and Protection
Functions
¾ Thermal management
system
t
Technical specification
VRB
VRB--ESS
Power/Capacity
2.4kW/54kWh
Voltage class
48V DC
B tt
Battery
St
Stack
kM
Modules
d l
1 2kW 2 iin series
1.2kW,
i
Energy Efficiency
up to 75% (DC
(DC--DC)
Operation condition
-20 ~ 40oC
Size (L × W ×H)
2.5
2.5×
×1.9
1.9×
×2.0 (m)
Telecom Station Installed in Dalian
6kW PV on the roof
Telecom Station
with load of 500W
2 kW/54kWh VRB
System Operation
Different loads were used to optimize the system
200W load
Charge > Discharge,
SOC increase
Cha
arge/Disch
harge
Power(W))
Operation data from Feb
Feb.26
26 to Apr
Apr.14
14
500W load
SOC stable
700W lload
d
Charge < Discharge
OC
CV (V)
Charge ≈Discharge,
Apr.14
Feb.26
SOC decrease
This PVPV-VRB system is suitable for 500W load,
which certify the original design.
Diesel g
generator
works to charge the
VRB, helping to get a
higher SOC.
Temperature Management System
¾ The temperature inside the VRB cabinet and the electrolyte
increase stably with the increase of environment temp.
¾ Inside temp. is 15~20oC higher than the environment temp. due
to the using of insulating materials.
¾ When the temp. inside is higher than 40oC, the heat emitter will
work.
Contents
¾ Challenges
g for VRB Commercialization
¾ Progress on Key Materials
¾ A PV
PV--VRB System for Telecom Station
¾ Large
L
Scale
S l VRB System
S t
Integration
I t
ti
A VRB System
y
for Smart Grid
Technical specification
VRBVRB-ESS
Power/Capacity
80kW/160kWh
Voltage Class
220V DC
System Efficiency (DC(DC-DC)
Large then 70%
Operation Condition
-20 ~ 40oC
Size (L × W ×H)
6.5×
6.5×2.6
2.6×
×2.8 (m)
R&D of 520kW/1MWh VRB for MW Class System
y
2011
5MW VRB for 30
30-50MW
50MW wind farm
Acknowledgments
c o edg e ts
¾National Basic Research Program of China (973 Program)
of Ministry of Science and Technology (MOST), Grant No.
2010CB227200.
2010CB227200
¾The Knowledge Innovation Program of the Chinese
Academy of Sciences (ACS)，
(ACS)，Grant No. KGCX2KGCX2-YWYW-322
322--2
Many thanks go to MOST and ACS for
the financial support.
pp
Thank you for your attention.