48V Battery System Design for Mild Hybrid …...Custom Battery Solution for 48V Mild Hybrids 0 5 10 15 20 25 0 5 10 15 20 25 LTO NMC A123 UltraPhosphate [m] Ω] Solution Comparison

©2016 A123 Systems, LLC. All rights reserved. ©2016 A123 Systems, LLC. All rights reserved.

Angela Duren 11 February 2016

48V Battery System Design for Mild Hybrid Applications

©2016 A123 Systems, LLC. All rights reserved.

Low voltage hybrids are a cost effective solution for higher volume impact on fuel economy requirements

OEM Portfolio Planning; A Balanced Strategy for Fuel Economy

Fuel Economy Requirements

EV

HEV

Micro-hybrid

sales volume

Mild hybrid

48V


48V mild hybrids are gaining maturity; should be transparent as start-

stop restarts are improved

• Powertrain efficiencies + Most mature technologies

+ Typically modest gains; except engine downsizing

+ Usually transparent to consumer, unless performance is sacrificed

• Light weighting + Somewhat mature

+ Large impact if implemented across many components

+ Somewhat transparent to consumer except possibly in repair costs

• Electrification + Varying maturity by technology

+ Full range of impact depending on battery/motor size

+ Dramatic variance in levels of consumer transparency

3

Weighing technology maturity and consumer acceptance

Fuel Efficiency Options

©2016 A123 Systems, LLC. All rights reserved. 4

Fuel Economy/ Emissions Impact

Two OEMs have tested A123 battery

in 48V systems coupled with 1.xL

engines, and average fuel economy improvement

projected is 12%

Low Voltage Electrification Steps


Attractive system cost per % fuel economy gain

48V Mild Hybrid Incremental Cost

DCT 8-speed (from 6 speed)

F150 700lb reduction

Start-stop

$0

$500

$1,000

$1,500

$2,000

$2,500

0 5 10 15 20 25 30

Incremental system cost ($)

Fuel Economy Improvement (%)

48V mild hybrid

Full hybrid

$55

$83

$87

$167

$35 48V mild hybrids are now

competitive among mainstream fuel saving solutions

$/%


2013 2014 2015 2016 2017 2018 2019

A123 Continues to Expand in Low Voltage

12V micro hybrid TBA

48V mild

hybrid

Start of Production

• Low voltage hybridization is a strategic focus for A123 Systems • A123 has now secured 9 low voltage customers globally, some with multiple programs • This experience has enabled insights in market trends and technical requirements


48V Battery Requirements are Diverse

• Drivers of 48V systems vary globally and among vehicle types

+ Fuel economy/ emissions improvement (aggressive charge pulses)

+ Electric super charger support/ engine downsizing (aggressive discharge pulses)

+ High power features such as e-A/C and e-Chassis

+ Combinations of the above

• Power requirements from OEMs globally

+ Peak charge power specifications have ranged from 2kW to 21kW

+ Peak discharge power specifications have ranged from 6kW to 18kW

• Various package locations considered affect battery life & dimensional requirements

7


Sizing a 48V Battery for Mainstream Markets

• Lithium-ion cells used for HEV applications have power/energy ratios that work well in 48V applications, but most are not sized properly to balance energy, thermal requirements, and cost

• Energy throughput requirements for 48V battery systems range from 100-200Wh

+ Sizing toward the maximum of 180-200Wh yields approximately 4Ah capacity at EOL

• Assuming 50% capacity needed for usable energy window and capacity fade over life, approximately 8Ah BOL capacity is required

• Each lithium-ion chemistry has different requirements that might change this size factor slightly, but this is a good starting point for a chemistry fit comparison

8


• Considerations of market solutions + Cost will limit favorability of LTO in this application due to inherent series cell counts

+ NMC and LFP have most potential for mainstream success based on cost

+ Higher impedance of NMC makes active cooling a basic system requirement

• A123 concluded that LFP could be optimized to further reduce impedance and potentially reduce/eliminate the need for active cooling in most 48V applications

9

Considerations for 48V mild HEV battery solutions

A123 Chemistry Solution Portfolio

EV PHEV

EV w/ fast charge HEV Single Battery Micro-Hybrid EV

PHEV

EV w/ fast charge HEV 12V Single Battery (Europe/VDA)

48V Hybrid

High Energy

Dual Battery/ Aux 12V Micro-hybrid

Transportation Battery Solutions

High Power

LFP

LTO NMC (13s)

(14s)

(20s)


8Ah prismatic cell

Introducing UltraPhosphate™

0%

20%

40%

60%

80%

100%

Cathode Anode Electrolyte Loading

Impedance Change by Attribute

Nanophosphate UltraPhosphate

UltraPhosphate improvements total 65% additional power over previous HEV design

8Ah UltraPhosphate™

[48V]

14Ah Nanophosphate®

[HEV]

HEV Electrode High P/E

Ultra Electrode Extreme P/E


Custom Battery Solution for 48V Mild Hybrids

0

5

10

15

20

25

0

5

10

15

20

25

LTO NMC A123UltraPhosphate

Pac

k im

ped

ance

[mΩ]

RT

10

s C

har

ge P

ow

er [

kW]

Solution Comparison Scaled to 8Ah

RT 10s Pack Charge Power [kW] Pack impedance [mΩ]

LTO NMC UltraPhosphate

COOLING Not required in

most applications

Usually required due to

higher impedance of

NMC

Not required in most

applications

COST 40-50% more

cells for voltage match

Lowest cell count and

reuse of xEV electrodes

Low cell count and optimal

power density

Typical peak charge power requirement for 48V mild

HEV

UltraPhosphate : very low impedance supports reduced system complexity

without active cooling


• Packaging volume, weight, and noise reduction + Reduces battery pack dimensions with elimination of cooling

components

+ No clean air-duct routing

+ No fan noise

+ No cabin pressure concerns

• No thermal integration for OEM

• Reduced vehicle system cost

12

A simpler and more cost effective solution

Benefits of Eliminating Battery Cooling


C-sample, sourced for production in 2017

48V UltraPhosphate Battery Specification

Specification Unit Performance

Pack Configuration - 14s1p

Chemistry - UltraPhosphate

Capacity Ah 8

Minimum Voltage* V 24

Nominal Voltage V 46

Maximum Voltage* V 54

SOC Range % 30 - 80

10s Discharge @25°C, BOL, 50% SOC kW 15

60s Discharge @25°C, BOL, 50% SOC kW 7.5

10s Charge @ 25°C, BOL, 50% SOC kW 16

60s Charge @ 25°C, BOL, 50% SOC kW 9

Usable Energy BOL @ 25°C Wh > 180

Mass kg 8

Communication Protocol CAN

Length x width x height mm 304 x 108 x 95


48V Battery Life Projection without Active Cooling

• Cycling in Shanghai hot climate 2.5h/day for 365 days/year

• 1.4 MWh yearly energy throughput

• 23% impedance growth over 10 years

NEDC Drive Cycle Battery Temperatures in Shanghai


Cold crank gap with lead-acid addressed

UltraPhosphate also supports 12V Starter Battery

0

100

200

300

400

500

600

700

800

900

1000

lead-acid AGM12V 60Ah

A123 Gen212V 60Ah

A123 Gen312V 60Ah

Cold Cranking Amps (7.5V minimum for 10 seconds*)

-18degC

-30degC

A123 has recently achieved parity with lead-acid cold crank performance at -30oC, erasing

the performance barriers to mass market

* Tested to BS EN 50342-1 HE Electrode High E/P

8Ah UltraPhosphate™ 20Ah

UltraPhosphate™

Ultra Electrode Extreme P/E


Summary

• System costs of 48V architectures are competitive with other fuel saving technologies, especially with regard to cost per percent improvement and consumer acceptance

• Active battery cooling is an obstacle for mainstream solutions which can be solved with battery cells designed specifically for the 48V application

• A123 Systems’ 48V UltraPhosphate battery is a compact design which can support vehicle architectures designed for fuel economy improvement without active cooling

16


Documents

48V Battery System Design for Mild Hybrid …...Custom Battery Solution for 48V Mild Hybrids 0 5 10 15 20 25 0 5 10 15 20 25 LTO NMC A123 UltraPhosphate [m] Ω] Solution Comparison