Bipolar Nickel Metal Hydride Battery Development and Testing

DOE ENERGY STORAGE SYSTEMS RESEARCH PROGRAM

ANNUAL PEER REVIEWNovember 2 – 3, 2006, Washington, D.C.

James Landi jlandi@electroenergyinc.com203-797-2699

Program Objectives and Benefits

The objective of this program is to further develop the bipolar NiMH battery design to be used in high-energy and high-power energy storage applications.

– Build and demonstrate large-format batteries– Demonstrate these batteries in present and future applications

The bipolar NiMH battery could provide the following benefits: – Improve efficiencies by reducing transmission peaking losses

and shifting peak demands. – Reduce power and voltage sag to users.– Provide an efficient method to distribute backup energy/power

for utilities to ensure uninterruptible service to their customers. – Increase reliability of solar and wind systems that require energy

storage.

Program History

This program commenced September 2005, and is a continuation of previous development and demonstration programs.

Previous Accomplishments– Built and delivered a 600 V, 35 kWh, 20 kW Inverter battery system

Effort was in collaboration with First Energy Testing done by EPRI Solutions in Knoxville, TN

– Built a 500 V, 100 kVA UPS battery system, replacing ultra-capacitors– Built and delivered a 48 V, 50 Ah battery for a 3 kW UPS system– Successfully demonstrated a high power 40 kW, 350 V battery module

Present Program Milestones– Market Assessment– Design and Performance Improvements– System Builds and Demonstrations

EEI’s Bipolar Wafer Cell Battery Design

– Current flows perpendicular to all electrode surfaces

– Active materials are efficiently utilized, minimizing internal resistance

– Flexible form factor – 25% higher power– 25% less volume– 25% lower manufacturing cost– Environmentally friendly– Excellent life

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Two Bipolar NiMH Battery TypesHigh Energy NiMH Thicker/higher capacity electrodes

– High Energy/Lower power per unit weight and volume >50 Wh/kg, >140 Wh/L 35 W/kg, 100 W/L – Continuous

12 V to >600 V systems

High Power Applications Thinner/lower capacity electrodes High power/Lower energy per unit weight and volume

– >1 kW/kg, >2.6 kW/L - <10 second pulse– >30 Wh/kg, >80 Wh/L

12 V to >700 V systems

Electro Energy’s Market Assessment of High Power and High Energy Storage

EEI is conducting an ongoing market assessment to identify opportunities and pilot demonstrations for the bipolar batteries

Three market segments identified as prime candidates for bipolar battery applications– Electric Utilities– Critical Infrastructure Service Providers– Multi-Tenant Buildings

Energy storage solutions have two significant hurdles to overcome:– Education: Understanding the benefits associated with batteries– Investment: The economics of battery technology remains a

barrier

Design Improvements

Optimized negative-to-positive ratio resulting in improved performance and increased cycle life.

Improved electrode production processes– Established a continuous nickel foam based production process

for energy cells– Developed in-house capability to produce hydride electrodes for

energy cells– Developed a thin coating process for nickel and hydride

electrodes for power cells Implemented an automatic electrolyte filling process Developed and implemented a sealed stack formation process Investigated alternate materials leading to cost reductions

Cell Balancing System EEI has been utilizing a commercial cell balancing system to balance

every 5, 10, 15, 20, or 30 cells in battery systems Results in improved capacity, reduced heat, and increased efficiency

EEI 40 Cell Module Testing (Capacities With and Without Balancing System

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Cycle

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Charge_Capacity Discharge_Capacity

EEI 20 Cell Module (Capacities With and Without Balancing System)

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Cycle #

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acity

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Typical Pack Shows Greater than 5% Capacity Increase

Severely Unbalanced Pack Shows 100% Capacity Increase

EEI 4 kW Inverter Peak Shaving/Back-Up System

•4 kW Inverter

•1.5 kW Generator

•3 – 1 kWh Batteries (Each 48 V, 20 Ah)

EEI 4 kW Inverter Peak Shaving/Back-Up System

EEI 4 kW Inverter - Peak Shaving and Back-Up Operation

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Time (min)

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Grid Power Generator Power Inverter Output Power Battery Power

Peak Shaving Back-Up Peak Shaving/Battery Recharge

EEI 4 kW Inverter Battery Performance

EEI 4 kW Inverter System - Battery Performance

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rent

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ge (V

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Batt_I Batt_V

Peak Shaving Back-Up Peak Shaving/Battery Recharge

3 kW UPS System

•3 kW UPS System

•1 kWh Battery (48 V, 20 Ah)

3 kW UPS System – Battery Data3 kW Inverter System Battery Performance

Charge and 5 Minute 1500 W Loads

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5 Minute 1500 W Load on Inverter

100 kVA/ 500 V High Power UPS System

Module Design•Five 39-Cell Stacks in Series

•5 Ah, 250 V

•6.62” x 15” x 11.5”, 100 lbs

Complete System: •2 Parallel Strings of 2 Modules Series

•5 kWh, 100 kVA

•10 Ah, 500 V

Actual Testing System•1 Strings of 2 Modules in Series

•2.5 kWh, 50 kVA

•5 Ah, 500 V

100 kVA UPS Battery 1-Day Test Profile (50% Load) Cycles 793-804

Battery System has Maintained Consistent Performance Through 800 Cycles

100kVA UPS Battery System 1-Day Test Profile 12 Cycles (793 - 804)

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String 1 Volts Mod 1 Volts Mod 2 Volts DC String Amps

100 kVA UPS Battery Daily Energy In and Out (50% Load), at 800 Cycles

100kVA UPS Total Energy In/Out for Each Day (50% Load)

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Day Number

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or O

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h)

Total WH Out Total WH Ret

Energy Out of Batteries

Energy In To Batteries

Battery System has Maintained Consistent Performance Through 800 Cycles

Plug-In Hybrid Electric Prius With Electro Energy’s Bipolar Nickel Metal Hydride Battery

Module Configuration Battery System

60 cells, 15 Ah, 73 V, 1.1 kWh Two parallel strings of three modules in series

60 lbs 21.25” x 39.00” x 8.00”, <400 lbs

All electric range: 20-22 miles

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Plug-In HEV - 19.7 Mile Drive (All-Electric)PHEV Battery Discharge Profile - Parallel with HEV Battery

21.3Ah, 4.5kWh removed – 0.92Miles/Ah, 4.38Miles/kWh)

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PHEV Prius Test Run07-11-06

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Elapsed Time (Secs)

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tage

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Battery VoltageB tt C t

Summary and Conclusions

Bipolar cell design was optimizedModule and battery performance was improved

through cell/stack balancingBipolar cell production processes were

developed for volume manufacturingHigh-voltage modules/systems were tested,

achieving multiple cyclesThe bipolar NiMH batteries were demonstrated

in multiple applications

Continued and Future Efforts

Manufacturing Process Development

Bipolar Battery Module Optimization –144 V, 6 Ah High Power Modules–75 V, 20 Ah Energy Modules–110 V, 15 Ah Energy Modules

Battery Systems Pilot and Demonstration

Company Developments April 2006, acquired assets of battery facility in Gainesville,

Florida area formerly owned by Energizer — Leased 200,000 Ft2 of manufacturing space– Simultaneous with acquisition raised working capital to be

used for: Equipment up-grades New Equipment

Gainesville acquisition will accelerate commercialization and growth plans:

High volume electrode manufacturing for Li-Ion and Ni based products

Highly automated capabilities for 18650 Li-Ion cells –30m/yr

Equipment can be adapted for bipolar battery manufacturing

High volume commercialization of bipolar Ni-MH batteries Leverage bipolar expertise developed for Ni-MH into

Lithium-Ion batteries Gainesville facility provides EEI with necessary manufacturing

assets to become a leading supplier of specialty rechargeable batteries in North America

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Acknowledgements

Electro Energy, Inc. has received funding for this effort from the

Department of Energy.

In particular EEI would like to thank Dr. Imre Gyuk

of The Department of Energy

Nancy Clark and David Ingersoll of

Sandia National Laboratories for Program Management