Nanostructured Si-C Anode for Lithium- Ion Batteries ·  · 2014-01-23Lithium Ion Rechargeable Batteries Technical Handbook, ... Less chemistry & quantum effect ... MO-C Tsinghua-physics

Nanostructured Si-C Anode for Lithium-Ion BatteriesLetian Wang

2014.1

Outline

• Li-ion Battery

• Nanostructured Si-C

• Possible research

Power Source Comparison

Energy Storage Market

• Fuel cells 5/8/09 (CNET News) – “DOE to slash fuel cell

vehicle research”

“[...] many years from being practical.”

Portable, Safety

• Supercapacitors Energy density<30 Wh/kg

Li-ion: <160 Wh/kg

• Battery NiCd: Toxic

NiMH: Expensive, Capacity, Memory

Li-ion: Best

2012 World Market Share over 38,000,000

kWh, 20 billion $http://li.itdcw.com

finance.sina.com.cn

Definition• Li-ion battery

LiC6+LixCoO2=LiCoO2+C

Anode: C

• Li battery

Li+MnO2=LiMnO2

Anode: Li

• Other Li battery

Li-S

Li-Air

Application-Current

Energy (Distributed Storage for Renewable Energy)

Model S-Tesla LIB -Tesla Household-Solar City

Macro

Application-Future

Small scale energy storage

MEMS and Microfluidic

Minituation

Flexible

Sensors Electrode

Biological Matter

Heavy Metal, Toxics

Micro

Companies

China

• Lishen力神，ATL，BYD比亚迪 全球前十锂离子电池生产厂商

• Shanshan杉杉 上海 世界最大锂离子电池综合材料供应商

• 贝特瑞 深圳 世界最大锂离子电池电极材料供应商

World

• Korea

Samsung SDI

LG LGC

• Japan

Sanyo

Sony

MBI, Maxwell, NEC

• USA

A123

Mechanism

Anode-lose e-Negative

Cathode-gain e-Positive

Cathode• Discharge

• Charge

• M: transition metal

LiMO2 - xe− ↔ Li1−xMO2 + xLi+

Li1−xMO2 + xLi+ + xe−↔LiMO2

Janina Molenda and Marcin Molenda ,InTech, 2011

Critical to:

Mass capacity

Vcell

Anode

• Discharge

• Charge

• Material-Graphite

Candidates：Silicon, Carbon, Tin

LixC6 - xe− ↔xLi+ + 6C

Charles de las Casas, Wenzhi Li, Journal of Power Source, 2012

xLi+ + xe− + 6C ↔ LixC6

Electrolyte

• Solid Electrolyte Interphase (SEI)固体电解质中间相 The decomposition of electrolyte

Prevent reaction between the electrode and the electrolyte

Ionically conductive and electronically insulating, stable

• Lithium salts

LiPF6, LiBF4 or LiClO4

• Organic solvent

ethylene carbonate(碳酸乙酯）

dimethyl carbonate（碳酸二甲酯）

diethyl carbonate（碳酸二乙酯）

Ionic liquid

Performance Characteristics

• Full Cell Characteristics Charge

Discharge

Discharge Curve(votage-discharge)

Storage

Cycle Life(capacity-cycle)

• Electrodes Capacity per mass or volume

Capacity vs Cycle

• Cost

Lithium Ion Rechargeable Batteries Technical Handbook, Sony

Risks and Safety Issues

• Linked to materials, size, chemistry.

• Common factors

Heat

Flammable: organic electrolytes and polymers

Lithium: low melt point (180℃) and react with water

Material aging, failure

Low temperature

Leakage

Toxic matter

• Stack design

O’hara et al. Battery Technologies: A General

Overview & Focus on Lithium-Ion, Intertek Co

Challenge For Li Battery

Cathode

• Limited Capacity

• Safety concern at deep charge

Anode

• Conductivity-Power density

• Fading

• SEI layer formation

Research Topics• Material

Easy transport through shorter distance and greater surface area

Durable and reliable: expansion

Phase transition

SEI formation

• Transport

Mass and charge transport

Ionic diffusion

Electron-transfer kinetic;

Nano design for energy

Portfolio of solar/thermal/electrochemical energy conversion,

storage, and conservation technologies, and their interactions

Baxter, Jason, Gang Chen et al. Energy & Environmental Science 2009

Gang Chen MIT, NSF Nanoscale Science and Engineering Grantees Conference, 2011

Nanostructured Electrodes• Benefit

Larger space and active site for Li insertion

Larger contact surface for electron conduction

Shorter diffusion length of electrons and ion

• New Challenges Reduced charge/discharge cycles

Increased side reactions of electrode and electrolyte

Higher self-discharge

Fabrication cost

• Research Issues Capacity- Insertion chemistry-Diffussion

Conductivity-Electron transport-Crystalination

Rate-Ion transport-Porosity

Cycle-Pulverization & contact-mechanical

Create unique pathways!

Cathode

• Current Material

Material Struc

ture

Capacity(mAh/g

)/Conductivity

（S cm-1)

Benefit Drawback

LiCoO2 Layer 274(140)/10-4 Capacity,

lifecycle

Fabrication

Unstable

Cost

Toxic

LiMn2O4

LiMnO2

Spinel

Layer

200(100)/10-3

285(100)

Capacity

Cost

Cycle life(Mn2O4 fading)

Unstable

LiNO2 Layer 200() Capacity

Cost

Untoxic

Fabrication

Unstable (successive

phase transformation)

Cycle life

LiNixCoy

MnzO

Layer 250(160) Cost Capacity

LiFePO4 Olivin

e

140(100)/10-9 Cost

Stable

Cycle life

Low temperature

Packing density

Capacity

Stability vs CapacityClose to chemistry & quantum effects

Bottleneck!!

Anodes• Graphite and Hard Carbon

Low capacity (372mAh/g)

Low ion transport(10-6cm2 /s-1)

• Other Candidates Metal Oxide- LTO(钛酸锂)

Zero volumetric change

Low capacity

Alloy-Si Sn High capacity

Large Volumetric change

Metal Nitride/Sulfide Normal-MS2

• New Si-C

MO-C

Si-Polymer

Research Trend

5 years of Web of Knowledge Institutions

Anode Total 14951

Carbon 5224

Silicon 1247 Stanford

Si&C 457 (354/188) Stanford,

Gatech

Cathode Total 16,100

LiFePO4 998

LiFePO4&C 430(200/90)

Full Cell NiSn-LiMnO2 2013 UIUC,2013

Si-Graphene 2013 Gatech,2014

Key words: Li ion battery; carbon; anode; cathode; silicon; LiFePO

Silicon Anodes

Benefit

• High theoretical capacity

• Low discharge potential: below 0.5V

• Low cost

Drawback

• Pulverization, electrical contact↓, capacity fading

5Si + 22Li+ + 22e- ↔ Li22Si5

⇒ 4200 mAh/g

Boukamp, Lesh, & Huggins, J. Electrochem. Soc. 1981 Yi Cui, Nature Letters, 2007

Silicon Composite

Doping: C, B, Ni

Coating: C, SiO2

Nano matrix composite

Graphite

MgO/C

TiO2

Polymer

Terranova et al. Journal of Power Source 2013

Researchers-Anodes

Yi Cui -Stanford

• Lithium-Ion Battery

Si Nanowire Anode (2007)

Silicon-Carbon (2009)

Silicon-Polymer (2013)

• Other

Photovoltaic

Printable Energy Device

Nanowire filters

Nanoscale Tools: In-situ TEM

Gelb Yushin -Gatech

• Carbon Materials

Lithium-ion Anodes

Lithium-Sulfur

Supercapacitor

Researcher-Full Cell

• UIUC-3D microelectronic full cell

Pikul et al. Nature Communication 2013

William P. King

Sihan Chen(Lab Alumnus)

AFM-based tDPN (thermal dip-pen nano lithography) Silicon-based devices and circuits.

Tsinghua LIB• 核研院202室：

• 姜长印，万春荣，何向明，李建军，王莉，任建国

• 电极材料（全面），全电池

• 物理系&富士康纳米中心

• 范首善（院士），王佳平

• 碳材料以及氧化物(MO)负极

• 材料学院

• 伍晖（Stanford Yi Cui博士后），唐子龙，朱静（院士）等

• 水凝胶与硅基负极，碳材料，全固态锂电及其锂离子传输

• 深圳研究院

• 康飞宇（材料学院），李宝华

• 碳材料出发,碳硅电极

Object：Si-C Anodes

• Anodes

Transport is more important

Less chemistry & quantum effect

• Carbon Nanotubes and Graphene

Electric, thermal and photonic properties

Mechanical strength, flexibility and resiliency

• Silicon

Semiconductor properties: PV and TPV

Why Si-C？

• Broad Future of Si-C

Cost: abundance and massive fabrication

Application: Energy conversion and storage, Sensors

Flexibility: Next generation wearable electronics

• To be consistent with our groups other projects

Si nanowire (Sihan Chen)

CNT fabrication (Dong Liu)

C coated with Si

Carbon

black

CNT

Graphene

Si coated with C• Carbon on Si NP

• Carbon on Si NW

Carbon particle on Si NW (2009)

3324mAh/g (highest ever)

Tsinghua MSE Jing Zhu

CNT on Si NW (2012)

Core-void-shell

• Nanopaticle

• Nanotube

• Nanowires

• Liqiang Mai

Combination & Hierarchical

Advanced methods

• 2D+1D

• Encapsulation

Design Strategy• Operation:

Addition

Coating

Encapsulating

Voiding

• Material Matrix

Si, C NP

Si, C NW

Si, C Sheet Carbon black-Si coating- Encapsulation

?Create Hierarchy and Void

Silicon + Carbon AnodesName Fabrication Benefit Drawbacks

Nanoparticle (0D) Simple Milling Agglomeration

2004 Porous C-Si Pyrolysis，Carbonization，CVD

Massive fabrication

Core-Shell

Yolk-shell

Nanowire (1D) Simple

2007 Core-shell

(Coating)

C-Si

Si-C

C-Si-C

Cracking and

nanopore

Core-void-shell Void Separate & buffer

Graphene (2D) Coating/Multi

Coating

C-Si-C

Combination

&Hierarchical

NW+NP

NW+NW

NP+NP

Hierachical both electrical and

thermal conductivity

flexible and strong

Micro-nano-

sphere

Encapsulating, Separate Si

Problems• Solid Electrolyte Interface (SEI)

Not too thick

Object:

Hui Wu, Yi Cui et al. Nature Nanotechnology 2012

Li-ion batteries show limited calendar and

cycle life--less than 2 years

Problems

• Nanopore

Liangbing Hu, Anyuang Cao, Yi Cui, Advanced Energy Material 2011

Problems

• Cracking

(In Situ)

Research Direction

• Material fabrication

Design New Structure

Optimization: the size and distance

Massive Fabrication

In situ Studies

• Mechanism

Ion diffusion

Thermal

Electron

Lithiation caused Structural Change

Research Proposal• Phase 1

Fabrication of Si-Carbon anode

• Phase 2

In situ characterization using AFM or TEM

Ionic Transport during the Li loading process

Thermal properties for lithium-loaded anodes.

• Phase 3

Full Cell with integration of cathode (LiFePO4/C)

Conclusion• Silicon-Carbon anode is ready for research due to

its importance as well as our lab’s experience

• 2. Research proposal and schedule

• 3. Possible topics regarding the transport and thermal properties

• 4. Discussion for next step

Liqiang Mai Note• Na离子电池

• 单纳米线电池

• 包覆

• 三维，纳米卷，膨胀

• 看物象，看成分

• Li-air电池

Power Source Comparison

Li-ion batteries have proved optimal for most mobile electronics and

competitive for hybrid and electric vehicles

Technology Power

density

Energy

density

Lifetime Efficiency

Fuel cells Low/moderate High Low/moderate Moderate

Supercapacitors Very high Low High High

Nanogenerators Very low Unlimited Unknown Low

Li-ion w/ graphite Moderate Moderate Moderate High

Li-ion w/ Si NW Moderate High Under

investigation

High

Piezoelectric

nanogenerat

ors:

Wang, ZL, Adv. Funct. Mater., 2008

45

Next Generation LIB

Nanostructures of the cell• Nanostructured architectures

• 1.1 Three dimensional thin–films

• 1.2 Interdigitated electrodes

• 1.3 Concentric electrodes

• 1.4 Inverse opal

• 1.5 Nanowires and nanotubes

• 1.6 Aperoidic electrodes

AnodesName Benefit Drawbacks Researcher

Metal Oxide

(MO)

LTO

(Ti)

Surface area

Zero volume change

Capacity (500-1000)

lower inherent

voltage，low energy

density

Tsinghua-核研院商业化

MnO

LVO

Carbon Graphene/CNT/Ha

rd carbon

Commercialized

Low cost

核研院商业化

Alloy Si High capacity(>1000)

Low charge potential

Safety

Volumetric change Stanford

中科院化学所Tsinghua-核研院

Sn UIUC

Metal

Nitride/Sulfide

MS2（Mo W Ga Nb

Ta）Li7MnN4

Good capacity

(500-1000)

Defect-volumetric

change

Expensive

Nano

Composite

Si-C Yi Cui Stanford

Yushin,Gatech

材料学院，深研院（973），核研院

MO-C Tsinghua-physics

Si-Polymer Berkely Stanford

Tsinghua MSE

Nano Energy Portfolio• Storage

Batteries

High Energy Density

Capacitors

High Power Density

Portfolio of solar/thermal/electrochemical energy

conversion,

storage, and conservation technologies, and their

interactions

Baxter, Jason, Gang Chen et al. Energy & Environmental Science 2009

Thermal

Transpo

rt

&

Interfac

e

Material

Thermal

Storage

Material

Thermophysics Current Focus

• Tradition-Heat conduction Now: Electron-Phonon

Goodson, Li Shi, C Dames

• Tradition-Radiation Now: Photon-Phonon

Gang Chen, Zhuoming Zhang, Sheng Shen

• Tradition-Phase Change Now: Hydrophobic Surface, Nanofluid, Nano porous

material

S. V. Garimella, EN Wang

• Others Chemical

Cui Yi, Xiaolin Zheng

Origin Current

Focus

Applicati

on

Researchers

Goodson, Li Shi, C Dames, Fisher

Gang Chen, Zhuoming Zhang,

Sheng Shen

S. V. Garimella, EN Wang, Fisher

Cui Yi, Xiaolin Zheng

Nanoscale design• Conversion

Wavelength

• Transport

Mean Free Path

Baxter, Jason, Gang Chen et al. Energy & Environmental Science 2009