4 石墨烯用作锂离子电池负极材料的电化学性能研究

石墨烯用作锂离子电池负极材料的电化学性能研究

Dong-Lin Zhao (赵东林)国家碳纤维工程技术研究中心化工资源有效利用国家重点实验室2012-8-20

Outline (目录)z z z

Uniqueness of graphene(石墨烯的特性) Controllable synthesis of graphene(石墨烯的制备) Graphene anode materials for LIBs(石墨烯用作锂离子电池负极材料) Doped graphene anode materials for LIBs (掺杂型石墨烯用作锂离子电池负极材料) Graphene-based anode materials for LIBs(石墨烯复合材料用作锂离子电池负极材料)2012-8-20

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石墨烯定义:石墨烯是碳原子紧密堆积成单层二维蜂窝状 (honeycomb)晶格结构的一种炭质新材料，这种石墨晶体薄膜的厚度只有0.335 nm,是构建其他维数炭质材料 (如零维富勒烯、一维纳米碳管、三维石墨)的基本单元，具有极好的结晶性及电学性。完美的石墨烯 (grapheme)是二维的，只包括六角元胞(等角六边形);如果有五角元胞和七角元胞存在，会构成石墨烯的缺陷；少量的五角元胞存在会使石墨烯翘曲。

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石墨烯的特性:自从石墨烯被发现以来，其出色的性能在诸多领域显示出极大的潜力。其作为碳质材料的基本单元，是目前已知唯一且最薄的二维材料，理想的石墨烯片层结构具有 2630m2/g的超高比表面积和容量为744mAh/g的储锂容量，远远高于其他众多负极材料，同时具有优良的力学光学和热学等性质。它不仅能够满足对电极材料的导电率高且不与电解质发生分界或电化学反应的要求，而且提供了尽可能大的比表面积、成型性好、易于修饰和复合等诸多方面的优势。

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The Nobel Prize in Physics 2010

Andre Geim安德烈·海姆

Konstantin Novoselov康斯坦丁·诺沃肖洛夫

Andre Geim Born: 1958, Sochi, Russia Affiliation at the time of the award: University of Manchester, Manchester, United Kingdom Prize motivation:"for groundbreaking experiments regarding the two2012-8-20 dimensional material graphene"

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What Is Graphene?

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AK Geim et al., Nature Mater. 6 (2007) 183

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AK Geim et al., Nature Mater. 6 (2007) 183

New Types of QuasiparticlesFrom A Geim, Lecture at IMR CAS, 14 July 09

Schrödinger fermions =p 2/ 2m HE

r =cσ H p

Dirac particles

massive massless Dirac fermions chiral fermionsr =vσ H p F r 2 =σ / 2m H p

ky kx monolayer graphene bilayer graphene metals and 2012-8-20 semiconductors neutron stars and accelerators

Unique Physical Phenomenaz z

Ideal platform for quantum electrodynamics New Quantum Hall Effectz

Minimum quantum conductivity in the limit of vanishing carrier concentration Strong suppression of quantum interference effects

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Quantum Hall effect at RT (massless carriers and little scattering)

Klein Tunneling……

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AK Geim et al., Nature Mater. 6 (2007) 183

The Effect of Structure on the Electronic Structure of Graphenez

Number of layersMonolayer Bilayer Triple-layer Bulk graphite

The electronic structure rapidly evolves with the number of layers:z

Monolayer and bilayer graphene: zero-gap semiconductors; with one type of electron and one type of hole For three or more layers: several charge carriers; the conduction and valence bands overlapping More than 10 layers: approaching the 3D limit of graphiteAK Geim et al., Nature Mater. 6 (2007) 183 T Ohta et al., Science 313 (2005) 951 B Partoens et al., Phys. Rev. B 74 (2006) 075404

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The Effect of Structure on the Electronic Structure of Graphene

width and edge (graphene nanoribbons)

< 10 nm: semiconductor FET: on-off ratio of 107 at RT2012-8-20 MY Han et al., Phys Rev Lett 98 (2007) 206805

XL Li et al., Science 319 (2008) 1229

GRAPHENE’S SUPERLATIVES thinnest known material in the universe strongest material ever measured (theoretical limit) stiffest known material (stiffer than diamond) most stretchable crystal (up to 20% elastically) most impermeable (even He atoms cannot squeeze through) record thermal conductivity (outperforming diamond) highest current density at room T(million times of those in copper)

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highest intrinsic mobility (100 times more than in Si) lightest charge carriers (zero rest mass) longest mean free path at room T (micron range)………

Potential Applications (1)z

Electronic devicesz z

Single electron FET Spin-valve and superconducting FET

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NEMS devices and sensors TEM support membrane

AK Geim et al., Nature Mater. 6 (2007) 183 HB Heersche et al., Nature 446 (2007) 56 2012-8-20 F Schedin et al., Nature Mater. 6 (2007) 652 JC Meyer et al., Nature 454 (2008) 319

Potential Applications (2)z z

Composites Transparent conducting films Lithium ion batteries Supercapacitors Field emitters Dye-sensitized solar cells Catalysts…AK Geim et al., Nature Mater. 6 (2007) 183 S Stankovich et al., Nature 442 (2006) 282 DA Dikin et al., Nature 448 (2007) 457 X Wang et al., Nano Lett. 8 (2008) 323 T Ramanathan et al., Nature Nanotech. 3 (2008) 327 G Eda et al., Nature Nanotech. 3 (2008) 270

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The bright future of grapheneNew G transistors ICs Nanodevices Communication Display devices Solar cells Flexible devices High strength Electric conductive Lithium ion batteries Supercacitors Field emission Gas sensing Detection to Force, electron and mass Imaging Drug delivery

High mobility HF response High conductivity Good mech Prop Transparent High SSA Functionalizat ion Good stability 2012-8-20

Transparent conductive devices Composite materials

Electrode materials Single molecular sensors NEMS

Bio-medical devices

Outline (目录)z z z

Uniqueness of graphene(石墨烯的特性) Controllable synthesis of graphene(石墨

烯的制备) Graphene anode materials for LIBs(石墨烯用作锂离子电池负极材料) Nitrogen-doped graphene anode materials for LIBs (氮掺杂型石墨烯用作锂离子电池负极材料) Graphene-based anode materials for LIBs(石墨烯复合材料用作锂离子电池负极材料)2012-8-20

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Synthesis Methods of Graphene

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