Electric Vehicle Safety: Design & Research Alvaro Masias Energy Storage Research, Ford Motor Company ARPA-E Crash-Safe Energy Storage Systems for Electric Vehicles Workshop Denver, CO – November 12, 2012 Page 1 Table of Contents Design Research Page 2 Table of Contents Design Research Page 3 Power of Choice ELECTRIFIED VEHICLES TRIPLING PRODUCTION CAPACITY IN NORTH AMERICA BY 2013 Page 4 Ford Focus Electric 110 MPGe Advanced Li-Ion Battery 5 PASSENGER 25-30% smaller LIQUID-COOLED 23kWh FASTER CHARGING 50% lighter LITHIUM-ION BATTERY PACK MORE EFFICIENT BATTERY TEMPERATURES Page 5 Reliability Researching and developing modern electrified vehicles for decades 1996 1998 2004 2009 2010 Cell Testing and Research Ford Escape Hybrid Ford Ranger Electric Ford Fusion Hybrid Page 6 Focus Electric Battery Location BEV Upper Battery Pack is mounted in the trunk behind the second row seats. Lower portion of pack extends through trunk floor to the outside of the vehicle BEV Lower Battery Pack is mounted under the vehicle below the second row seats Page 7 Crash Requirements – FMVSS 305 30mph Rigid Barrier 30mph 50mph 70% Overlap 30 o Left & 33.5mph Left & Right V-to-V Left & Right Right o Angular 27 Crabbed Cart Frontal Crash Events Side Crash Events Rear Crash Events Page 8 Public Domain & Additional Ford Crash Testing 35mph NCAP 20mph Oblique th th% NCAP Left & Right Pole (5 /50 ) Rigid Barrier High Speed V-to-V Left & Right 40mph 40% Rear High Speed IIHS Offset V-to-V Left & Right Side 38.5mph NCAP Left & Right Side MDB 31mph Left IIHS Cart Page 9 FMEA Analysis Noise Factors & Potential Prevent Stress Failure Modes Effects Actions Normal Conditions Over Temperature No Effect Vehicle Level Design Actions Over Charge Protection Noise Factors Activated Over Discharge Pack Level Damage/ Design Actions Off-Normal Conditions External Short Retention Internal Cell Short Leakage Cell Level Failure Modes Design Actions Venting Fire/Flame Page 10 Vehicle, Pack & Cell Level Actions Pack Level Actions • Battery Pack Structure • Vent Management Sys • Pack Cooling Sys • Battery Controls Sys Vehicle Level Actions • Power Limits (Temp, Age, others) Cell Level Actions • Over Temp • Vehicle Structure • Over Charge/Discharge • Cell Chemistry • ENS Control • Vehicle Cooling Sys • Cell Balancing • Cell Design • Battery Sensors (V, I, T) • Vehicle Control Sys • Fusing • Cell Manufacturing (occurrence reduction) • Charging Control Sys Page 11 Typical Testing & Verification Examples of typical tests that may be conducted on battery cells, battery pack assemblies, and/or entire vehicles. Vibration, Shock, Battery Enclosure Mechanical Integrity Electrical Short Circuit, Over Charge & Electrical Discharge Protection High/Low Temperature Exposure, Environmental Thermal Shock, Humidity and Moisture Exposure, Corrosion, Immersion Page 12 Focus Electric – Vehicle Level Structural Components Unique Designed (Material &/or gauge revised) Structural additions for battery pack crash protection Page 13 Focus Electric – Battery Pack Level Structural Components Battery Pack Casing Casing modifications for enhanced crash protection Page 14 Focus Electric – Rear Body Structure Page 15 Table of Contents Design Research Page 16 Battery Safety Research Battery Safety Hazards Project Summary System: NHTSA Research Funding System • COTR Gorney (2yr) • Vehicle Lithium Ion Battery Hazard Test Method Development Mechanical Thermal Mechanical: Ford-MIT Alliance Funding • Prof. Wierzbicki (2yr) • Lithium ion battery mechanical crush modeling and prediction Thermal: Ford URP Funding • Prof. Sunderland/Stoliarov (3yr) • Lithium ion battery thermal hazard Electrical assessment & comparison Electrical: Ford-UM Alliance Funding • Prof. Mi (2yr) • Battery management system (BMS) controls & requirements Fundamental: TBA (Proposal Stage) Fundamental TBA • Prof. John Doe (1+1.5yr) • First Principles of Cathode / TBA Electrolyte Interactions Page 17 NHTSA Solicitation: Overview Scope HEV/PHEV/BEV Li-Ion Battery Develop Safety Test Methods & Purpose Performance Safety Metrics • Active – Single Failure Tasks • Passive – Single Failure + Loss of Control System • Mechanical: Crush, Penetration, Timing Vibration, etc. Solicitation 1/26/11 Fault • Electrical: Overcharge, Short Circuit, Proposal 4/21/11 Origin Overdischarge, etc. • Thermal: Fire Resistance, Thermal Award 9/30/11 Control, etc. Finish 9/29/13 Page 18 NHTSA Solicitation: Awards Primary Sub- contractor Page 19 Ford Approach: Overview • Goal: Repeatable vehicle level Li-ion based RESS safety performance test procedures • Approach: Define vehicle level performance tests which draw upon the cell, module and pack level information. Page 20 Ford Approach: Process Test Method Fault Tree Analysis Survey Development Testing Fault Tree Failure Mode Analysis & Analysis F Effects Analysis Refinement a • Design u • Design Independent l dependent t • Deductive • Inductive (Top Down) (Bottom Up) Iteration Chose FTA for NHTAS RESS Project • Broadly applicable (Design Independent) • Event Path Dependence (Multiple Fault Scenarios) Page 21 Ford Approach: Fault Tree Analysis Failure Categories Thermal Electrical Chemical Mechanical Page 22 Table of Contents Design Research Page 23 Great Products, Strong Business, Better World Page 24.