Figure Credit: Kenny Gruchalla and Francois Usseglio-Viretta, NREL

Matthew KeyserElectrochemical Energy Storage Group ManagerNational Renewable Energy Laboratory, Golden CO

Matthew.Keyser@nrel.gov

Electrochemical Energy Storage Overview

Agenda

• Introduction – Vehicle Electrification

• Types of Lithium Batteries

• Cost Targets

• Future Battery Materials

• Three DOE Priorities

– Extreme Fast Charging (XFC)

– Behind the Meter Storage

– Recycling

• Acknowledgements

Battery and Electrification - Introduction

• New York International Auto Show: more than 40 electrified vehicles

• EPRI: Utilities are proposing ~$3.7B in EV charging infrastructure

• Continental CEO: Next 15 years, in the powertrain arena “the train is out of the station” in transformation to electrification

• CEO of Daimler Trucks North America: For commercial vehicles “The beginning of the post internal combustion engine era”

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https://www.cummins.com/news/2018/04/23/cummins-puts-electrification-progress-display

Courtesy: Cunningham Brian, DOE, AMR, 2019

Battery and Electrification - Introduction

• Affordable

– Battery and Electric Drive System Costs

– Charge Management

• Secure

– Cybersecurity

– Materials supply and recycling

• Reliable

– Localized, behind the meter storage

– Vehicles powered from grid electricity

Courtesy: Cunningham Brian, DOE, AMR, 2019

Lithium Ion Battery Technology—Many Chemistries

Voltage ~3.0 - 4.2 V

Cycle life ~1000-5000

Wh/kg >150

Wh/l >400

Discharge -30 to 60oC

Shelf life <5%/year

Source: Robert M. Spotnitz, Battery Design LLC, “Advanced EV and HEV Batteries”

Many cathodes are possible

Cobalt oxide

Manganese oxide

Mixed oxides

Iron phosphate

Rich Li, Mn, or Ni mixed oxides

Many anodes are possible

Carbon/Graphite

Titanate (Li4Ti5O12)

Silicon based

Metal oxides

Many electrolytes are possible

LiPF6 based

LiBF4 based

Various solid electrolytes

Polymer electrolytes

Ionic liquids

Li-Ion Chemistry Characteristics

Samu Kukkonen, VTT Technical Research Centre of Finland (2014)

Anode/Cathode Combinations

Decreasing Energy Density

Graphite/LCO

Graphite/NCA

Graphite/NMC

Graphite/LMO-Blend

Graphite/LFP

LTO/NMC

Safety

Energy

Lifetime

Charge

Cost

Future Supply

LCO – Lithium Cobalt Oxide; NCA – Nickel Cobalt Aluminum; NMC – Nickel Manganese CobaltLMO – Lithium Manganese Oxide; LFP – Lithium Iron Phosphate; LTO – Lithium Titanate Oxide

Energy Storage: Battery Cost Story – The Past and Future

“Rapidly falling costs of battery packs for electric vehicles”, B. Nykvist and M. Nilsson; Nature, Climate Change; March 2015, DOI: 10.1038/NCLIMATE2564

95% conf. interval, whole industry95% conf. interval, market leadersPublications, reports, and journals

News items with expert statementsLog fit of news, reports, and journals: 12 ± 6% decline

Additional cost estimates without a clear methodMarket leader, Nissan Motors (Leaf)

Market leader, Tesla Motors (Model S)Other battery electric vehicles

Log fit of market leaders only: 8 ± 8% declineLog fit of all estimates: 14 ± 6% decline

Future costs estimated in publications

2005 2010 2015 2020 2025 2030

2,000

1,600

1,800

1,400

1,200

1,000

800

600

400

200

20

14

US$

/kW

h

DOE cost target $100/kWhw/ ultimate goal of $80/kWh

2012 DOE cost target $600/kWh

2018 DOE cost $197/kWh

2022 DOE cost target $100/kWh

Energy Storage: Battery Cost Story – The Past and FutureSy

ste

m C

ost

($

/kW

h)

$200

$600

$500

$400

$300

$100

Year

2014 2020 2022 20242012 2016 2018 2026

$197/kWh

Graphite/High Voltage NMC

Silicon/High Voltage NMC

2028 2030

Lithium-Metal or Lithium/Sulfur

$320/kWh (5x excess Li, 10%S)

~$80/kWh

Graphite/High Voltage NMC

Silicon/High Voltage NMC

Lithium-Metal & Li/Sulfur

• R&D Focus: Higher cathode capacity (220+ mAh/g), low/no cobalt, recycling, fast charge

• R&D Focus: Higher anode capacity (1000+ mAh/g), cycle/calendar life, fast charge

• R&D Focus: Solve cycle life/ catastrophic failure issues, reduce excess lithium, reduce excess electrolyte, reduce lithium metal cost

Courtesy: Cunningham Brian, DOE, AMR, 2019

Direction of Cathode/Anode/Electrolyte Research

• Cathode– Present – NMC is the material of choice for electric vehicles– Short term research - Reduce cobalt content in NMC – (1,1,1) → (5,3,2) → (6,2,2) → (8,1,1). Going to higher nickel

contents leads to stability and safety concerns.– Long term research – Lithium Sulfur - 500 Wh/kg compared to the present energy density of approximately 200

Wh/kg. However, we need to address polysulfide formation/migration before this will be successful.• Anode

– Present – Graphite is the anode of choice.– Short term research

• Combining silicon with graphite to increase the energy density

– Long term research• 100% silicon anode (>1000 Wh/kg) but need to address lithium being consumed by the solid electrolyte interphase (SEI) and the

factor of ~3 volumetric expansion• Lithium Metal – need to address how evenly/unevenly lithium is deposited on anode layer and we need to suppress dendrite

growth which can lead to internal shorts and thermal runaway. Lithium metal is typically being developed along side solid stateelectrolytes (SSEs) – SSEs should address thermal runaway.

• Electrolyte– Present – Generation 2 electrolyte – usually referred to as Gen 2 electrolyte and is EC (ethylene carbonate):EMC

(ethylmethyl carbonate) in a 3:7 by weight ratio combined with 1.2M of LiPF6 (salt). – Short term research - Flourinated compounds and ionic liquids. For XFC, need to work on transport properties to

make it successful.– Long term research – solid state electrolytes but need to improve (drastically) the ionic conductivity of these

materials.

Energy Storage: DOE R&D Portfolio

CHARTER: Develop battery technology that will enable large market penetration of electric drive vehicles

2022 GOAL: $150/kWh(useable)Critical materials-free with recycled materials and capable of fast charge

Energy Storage R&D

Battery Testing, Design, & Analysis

Battery Development

Applied Battery Research (ABR)

Battery Materials Research (BMR)

Courtesy: Cunningham Brian, DOE, AMR, 2019

Why is Extreme Fast Charging (XFC) Important?

• DCFC Increases BEV Utility– Yearly electric vehicle miles

(eVMT) traveled increases withuse of 50 kW fast charging

– Nearly 25% more miles driven annually when DCFC used for 1-5% of total charging events

Source: McCarthy, Michael. “California ZEV Policy Update.” SAE 2017 Government/Industry Meeting, Society of Automotive Engineers, 25 January 2017, Walter E. Washington Convention Center, Washington, DC. Conference Presentation.

Level 1

(110V,

1.4kW)

Level 2

(220V,

7.2kW)

DC Fast

Charger (480V,

50kW)

Tesla

SuperCharger

(480V, 140kW)

XFC

(1000V,

400kW)Range Per

Minute of

Charge

(miles)

0.082 0.42 2.92 8.17 23.3

Time to

Charge for

200 Miles

(min)

2143 417 60 21.4 7.5

• EVSE Comparison– XFC should be able to charge

a BEV in less than 10 minutes and provide approximately 200additional miles of driving range

Lithium Deposition on Anode Depends on Capacity Loading

• Greater EV driving range needs energy-dense electrodes

• Increasing lithium deposition (metallic gray) on graphite electrodes as a function of capacity loading

• Lithium may or may not removed during the following discharge subcycle

• In-situ methods to detect plating have appeared in the literature

• Stranded lithium may be a safety issue; abuse response after XFC is unknown

Graphite issue

Courtesy: Michelbacher, Chris; DOE, AMR, 2017

Heat Generation in Batteries

• Lithium-ion batteries have very good coulombic efficiencies that are as high as 99.7%. The small drop in efficiency is often traced back to mismatched properties among the different battery components.

• The source of heat occurs in three areas:

– Heat generation in the cell due to Joule heating is usually 50% of the heat budget of the cell.

– Heat generation from electrode reactions contributes 30% – 40% of the heat losses.

– Entropic heat generation contributes approximately 5% – 15% of the heat losses.

Discharge Efficiency Comparison of Energy and Power Cells

HEV: hybrid electric vehicle

Thermal storage

A partnership with the Buildings, Solar, and Vehicles Offices

• Focus on specific end user outcomes• Minimize cost of energy to user• Buildings are the largest electrical users. • EVs will be charged at buildings.• Demand charges need to be eliminated.• Grid impacts minimized.• Integration of PV is/will be common.

• Both electrons and heat need to be stored.• New batteries are needed• New thermal storage are needed

Behind-The-Meter Storage (BTMS) Low TRL Work Guided by System Level Thinking.

MISSION: Minimize the cost of recycling lithium ion batteries to ensure future supply availability of critical materials and decrease energy usage

Lithium Ion Battery Recycling R&D Center

17

• Department of Energy (DOE)o Dave Howell, Samm Gillard, Brian Cunningham, Steven Boyd, Chris

Michelbacher

• U.S. DOE National Laboratories o Argonne National Laboratory1, Idaho National Laboratory2, National Renewable Energy Laboratory3

• Contributing Teamo Shabbir Ahmed1, Ira Bloom1, Andrew Burnham1, Richard B. Carlson2, Fernando Dias2, Eric J. Dufek2,

Keith Hardy1, Andrew N. Jansen1, Matthew Keyser3, Cory Kreuzer3, Oibo Li3, Anthony Markel3, Andrew Meintz3, Christopher J. Michelbacher2, Manish Mohanpurkar2, Paul A. Nelson1, Ahmad Pesaran3, David C. Robertson1, Shriram Santhanagopalan3, Don Scoffield2, Matthew Shirk2, KandlerSmith3, Thomas Stephens1, Tanvir Tanim2, Ram Vijayagopal1, Eric Wood3, and Jiucai Zhang3

Acknowledgments

www.nrel.gov

Thank You!

Questions?

This work was authored in part by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided by U.S. Department of Energy Vehicle Technologies Office. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes.