Next Generation High-Energy Density Li-Ion -

transcript

Next Generation High-Energy Density Li-Ion Batteries

Marie Kerlau

Young Engineers + Scientists Symposium 2012 March 20th, 2012, Berkeley, California

1 Leyden Energy Proprietary

Agenda •  Presentation of Leyden Energy •  Current Issues in Mobile Device Designs

Relating to Li-ion Batteries •  Energy Density Challenges and How to Address

Them •  Silicon-Based Materials •  Conclusion •  Q&A

•  2007 – Leyden Energy founded

around acquisition of DuPont patent, spearheading the use of lithium-imide salt in battery electrolyte.

•  4 years of consequent R&D efforts led to the first scalable lithium-imide product launch by Leyden Energy in 2010

•  2011 - Series B Funding led by NEA, Lightspeed, Sigma, & Walden

A bit about Leyden Energy

•  100% backward-compatible manufacturing processes leveraging existing lithium-ion production lines

•  UL/UN certified products (UL1642 & UN/DOT tests).

•  Multi-sourced, Tier-1 OEM approved

manufacturing partners in Asia with global distribution supply chain. “Factory within a factory” – Leyden Energy’s QC engineers on-site.

•  US-based pilot manufacturing and testing facility for world-class quality control & rapid prototyping. Facilities based in Fremont, CA.

Leyden Energy’s Fremont , CA-‐based manufacturing, packaging and tes<ng capabili<es enable stateside rapid prototyping.

Scalable Manufacturing, Testing and Rapid Prototyping

•  UL/UN cer$fied products (UL1642 & UN/DOT tests).

US-‐based pilot manufacturing and tes<ng facility for world-‐class quality control & rapid prototyping. Facili<es based in Fremont, CA.

ü  Heat Test ü  Impact Test ü  Crush Test ü  Short Circuit Test ü  Overcharge Test ü  Forced Discharge Test … and other tests.

•  7 UL-approved products in 2011

Scalable Manufacturing, Testing and Rapid Prototyping

Leyden Energy Proprietary

LiPF6 + H2O = Trouble…

LiPF6 Hydrofluoric Acid is generated in reaction with H2O

DEGRADATION OF ACTIVE MATERIALS; GASSING; SHORTENED LIFECYCLE – ACCENTUATED BY RISING IN-DEVICE TEMPERATURE 6 Leyden Energy Proprietary

…Compounded by in-device heat

Mobile phone Tablet

Lithium Ion Technology Chemical produc$on of Hydrofluoric Acid causes bloa$ng, deprecia$on of func$onality.

Lithium Imide Technology Increased temperature range, no Hydrofluoric Acid produc$on, 3x performance improvement.

Li-imide™ Chemical Advantage

Anode LiPF6

Cathode

Anode Li-imide Cathode

Li-imide™ – Pouch cycling at 20/40°C (68/104°F)

Swelling over battery lifetime at 40˚C/104˚F

More battery capacity per volume (volumetric) and weight (gravimetric) means more power per charge, or the same power in smaller/thinner packs.

With near-optimal performance over calendar life inventory outlasts LiPF6 by 300% giving embedded products far more shelf life.

Performance exceeds Li-ion (LiPF6 electrolyte) batteries by roughly 3:1 with over 1,000 charge/discharge cycles at 100% DOD (depth of discharge)

Superior thermal properties allow the battery to operate and cycle at temperatures exceeding those of conventional Li-ion cells – from -20°C (-4°F) up to continuous use at 60°C (140°F).

Triple Cycle Life

Higher Energy Density Triple Calendar Life

Temperature Resilience

Lithium Imide: Never Compromise

Leyden Energy – Target Applications

All markets, especially the portable electronics market, require ever increasing energy density

Energy Density Challenge: Form vs. Function

“Customers demand longer runtime per charge” = higher energy density or larger Z height

“Customers demand thinner devices” = smaller Z height

No Moore’s Law for Li-ion

“Forget Moore’s Law — it’s nothing like that… Lithium ion, which clearly is the best baWery technology today, is flat, completely flat since 2003” Winfried Wilcke, IBM Source: hWp://green.blogs.ny$mes.com/2010/09/06/when-‐it-‐comes-‐to-‐car-‐baWeries-‐moores-‐law-‐does-‐not-‐compute/ 14 Leyden Energy Proprietary

Cycle life suffers with increase in energy density

LiPF6 based pouch cells at 40°C

Source: Leyden Energy

New Materials Are Needed to Boost Energy Density

Cathode

Electrolyte

Issues

High capacity materials have short cycle life

No candidate with high capacity at 4.2V (120-‐160mAh/g)

DegradaSon at higher voltages than 4.2V

Next GeneraSon Materials

Alloys (Si-‐ and Sn-‐ based) composites, oxides (SiO,SnO) (600-‐900mAh/g)

5V Mn-‐cathode solid soluSon system (300mAh/g)

Ionic liquids, 5V systems

Silicon

ELECTROLYTE

Cathode and Anode agnos$c

CATHODE

NCM, NCA, LCO and High-‐Voltage Cathode

Areas For Battery Innovation

Silicon: the Next-Generation High-Capacity Anode Material For Li-Ion Batteries

•  Si has 10x higher Li-‐ion storage capability than graphite Graphite: C6 ↔ LiC6 Theore$cal Capacity: 372 mAh/g

Silicon: Si ↔ Li4.4Si Theore$cal Capacity: 4200 mAh/g

•  Problem: up to 400% volume expansion during Li ions inser$on/extrac$on causes a rapid decrease in cycling stability •  Industry has been searching for silicon anode that works and is affordable

•  Lower Dimensionality

o  Nanowires, Thin Films

•  Carbon Matrix

o  Si Nanoparticles Embedded in Carbon Matrix

•  Transition Metal Carbon Alloys and Oxides

o  Armorphous Regions with Si and No Carbide Formed

•  High Porosity

o  Si Coated on Porous Carbon Black, Nanotubes, Porous Si

Approaches to Solve Si Volume Change Problem

Binder-Free Electrode: Si Growth on Metallic Support

Si Thin Film

Si Nanowires

1-‐Dimensional Expansion Reduces Mechanical Stress During Cycling

Lithia$on

Cracks, Peeling Cycling: 0.01-‐1.2V, 1C

Cycling: 0.01-‐2V, C/5

Lithia$on

Ø  High capacity but difficulty in handling nanowires makes it difficult to mass produce

Ø  Despite high ini$al capacity the film cracks upon cycling G.B. Cho, M.G. Song, S.H. Bae, J.K. Kim, Y.J. Choi, H.J. Ahn, J.H. Ahn, K.K. Cho, K.W. Kim, JPS 189 (2009) 738-‐742.

C. K. Chan, R. Ruffo, S. S. Hong, R. A. Huggins, Y. Cui, JPS 189 (2009) 34-‐39.

Leyden Energy Proprietary 20

Capacity m

Cycle Number

Coulom

bic Effi

Cycling: 0.01-‐2V, 0.2C

Carbon-‐Si Core-‐Shell Nanowires

Crystalline-‐Amorphous Core-‐Shell Si Nanowires

a-‐Si c-‐Si

Binder-Free Electrode: Si Growth on Metallic Support 1-‐Dimensional Expansion Reduces Mechanical Stress During Cycling

Cycling: 0.01-‐1V, C/5 Cycle Number

Coulom

bic Effi

Capacity m

Ø  Poor adhesion to substrate and high synthesis costs make this material difficult to handle/ manufacture

L.-‐F. Cui, Y. Yang, C.-‐M. Hsu, and Y. Cui, , Nano LeGers 9 (9) (2009) 3370-‐3374 .

L.-‐F. Cui, R. Ruffo, C. K. Chan, and Y. Cui, , Nano LeGers 9 (1) (2009) 491-‐495.

Silicon-Carbon Composite

Core-‐Shell Model (Si@C)

Grain-‐Matrix Model (Si/C)

Carbon Matrix Accommodates the Volume Changes Upon Lithia$on/Delithia$on

A`er LithiaSon A`er DelithiaSon As Prepared

Ø  Carbon matrix/coa$ng can only accommodate volume changes to a limited extent thus limi$ng cycle life

P. Gao, J. Fu, J. Yang, R. Lv, J. Wang, Y. Nuli and X. Tang, Phys. Chem. Chem. Phys. 11 (2009) 11101-‐11105.

Silicon-Carbon Composite

Granules: Si in Porous Carbon Matrix

Carbon Black

Si Nanowires

Pores Accommodate the Volume Changes Upon Lithia$on/Delithia$on

Cell po

) vs. Li m

Ø  Low energy density due to high porosity; consump$on of electrolyte due to high surface area

Ø  Nanotube agglomera$on upon cycling reduces cycle life

A. Magasinski, P. Dixon, B. Hertzberg, A. Kvit, J. Ayala and G. Yushin, Nature Materials 9 (2010) 353-‐359 .

M.-‐H. Park, M. G. Kim, J. Joo, K. Kim, J. Kim, S. Ahn, Y. Cui, and J. Cho, Nano LeGers 9 (11) (2009) 3844-‐3847.

Alloys and Oxides Inac$ve Phase Accommodates the Volume Changes Upon Lithia$on/Delithia$on

Alloy (Si with transiSon metals and metals: for example Mn, Co, Al, Sn)

Oxide (SiO)

Ø  Lower capacity than pure Silicon but volume change is smaller; lower 1st CE than the alloy

-‐Li+

Ø  Lower capacity than pure Silicon but volume change is smaller

M. Yamada, A. Ueda, K. Matsumoto, and T. Ohzuku, JES, 158 (4) (2011) A417-‐A421

K. Eberman, 3M Company, 29th Interna$onal BaWery Seminar in Florida (2012-‐5-‐16).

Conclusion

•  Consumer demand for higher-‐energy density devices creates

challenges to design thinner baWeries with longer run $me

•  The trade-‐off with Silicon anode material:

•  The highest-‐capacity Si (2000 to 3500 mAh/g) does not have a

cathode material to match such a high capacity, manufacturability

is ques$onable (costs + technical difficul$es), cycle life is limited

•  Lower-‐capacity Si (<1500mAh/g), with lower expansion rate and

manufacturing costs, longer cycle life, would enable higher-‐

energy density baWeries to be commercially available sooner

Headquarters 46840 Lakeview Boulevard Fremont, California 94538 Info@leydenenergy.com Phone: +1-510-933-3800 Fax: +1-510-445-1032

America/Europe Sales sales@leydenenergy.com Phone: +1-510-933-3855 Toll Free: +1-866-543-4877

China Unit 2911-2912 29/F International Chamber of Commerce Tower, Fuhua Rd. 3 CBD Futian District, Shenzhen, 518048 China asiasales@leydenenergy.com Phone: +86-135100-75409

Next Generation High-Energy Density Li-Ion -

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