Development of New Electrolyte and Electrode Materials for - - PowerPoint PPT Presentation

Osaka Prefecture University, Japan

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Kiyoharu TADANAGA, Akitoshi HAYASHI and Masahiro TATSUMISAGO

Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, Japan Mario Aparicio, Alicia Durán, Yolanda Castro, and Francisco Muñoz Instituto de Cerámica y Vidrio (ICV), Consejo Superior de Investigaciones Científicas (CSIC), Spain

Development of New Electrolyte and Electrode Materials for All-Solid-State Thin Film Lithium Batteries through Solution Process

SJ-nano symposium, Tsukuba, March 5, 2013

Osaka Prefecture University, Japan

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Members of the project

Osaka Prefecture University Professor Masahiro Tatsumisago (Leader) Associate Professor Kiyoharu Tadanaga Assistant Professor Akitoshi Hayashi 1 Post-Doc, 2 Ph-D students, 1 Master course student 1 Research assistant Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Cerámica y Vidrio (ICV)

• Dr. Mario Aparicio (Leader)

Professor Alicia Durán

• Dr. Yolanda Castro
• Dr. Francisco Muñoz

1 Post-doc, 1 Ph-D student,

Osaka Prefecture University, Japan

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Solid Electrolyte Substrate Negative Electrode Positive Electrode

Thin-film battery

10 μm

Thin film lithium batteries will be used in things like smart cards, RFID tags, and other low power portable devices.

Possible application of thin film lithium batteries

Osaka Prefecture University, Japan

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Large area and good quality, or nano-structured thin

films can be prepared

Chemical compositions of thin films can be controlled. Rather thick films are easily obtained.

Examples of preparation of thin film batteries by physical processes

Sputtering・・・LiCoO2, LiMnO2, LiPON（lithium phosphate oxynitride）… Pulse Laser Deposition・・・ LiCoO2, LiMnO2, Li-V-Si-O amorphous thin film

Advantages of solution processes Electrode and electrolyte thin films for all-solid-state lithium rechargeable batteries Solution processes are very attractive for the development of thin film batteries. Thin film battery is an important element in realizing next-generation sheet devices, as it needs to be formed as a small, thin-film device.

Osaka Prefecture University, Japan

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Our project attempts to develop electrolyte and electrode materials for all- solid-state thin film lithium batteries using solution processes, as a clean and efficient energy production and storage device. Safe, thin-film lithium secondary cells which are free from such hazards as liquid leakage and/or fires will be developed by employing electrolytes prepared from inorganic or inorganic-organic hybrid solid-state materials by using solution processes. Purpose of our project

Osaka Prefecture University, Japan

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Positive electrodes OPU: LiMn2O4 Solid electrolyte OPU: Li7La3Zr2O12 Li1.5Al0.5Ge1.5(PO4)3 CSIC: organic-inorganic hybrid Negative electrodes OPU: Li4Ti5O12 CSIC: Li4Ti5O12

Current collector: Au Current collector: Au Substrate Pt, Au, Ti, Pt/Si, SiO2 glass, , etc.

Conceptual schematic of this project

Multi layered battery

Further development

Micro patterning

Osaka Prefecture University, Japan

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Solution-based processes used in OPU, for the preparation

• f electrode and electrolyte thin films

・Sol-gel process ・Mist-CVD process ・Electrophoretic deposition of particles prepared by sol-gel ・Aerosol deposition of particles prepared by sol-gel Solution-based processes used in OPU, for the preparation

• f electrode and electrolyte thin films

・Sol-gel process ・Mist-CVD process ・Electrophoretic deposition of particles prepared by sol-gel ・Aerosol deposition of particles prepared by sol-gel

Solution-based processes

Osaka Prefecture University, Japan

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Mist CVD process Mist CVD process

Features

• 1. This process does not need vacuum systems because it is operated at atmospheric conditions.
• 2. Various precursor solutions can be used for the source, including innocuous and nonpoisonous ones.
• 3. This process possesses various advantages such as: safety, cost-effectiveness, environmentally

friendly, and the ability to apply to various types of materials. In the mist CVD process, aqueous solution of starting material is ultrasonically atomized to form mist particles with a size of about 3 μm, and mists are transferred by a carrier gas to the substrate to form thin films. Mass Flowmeter Gas

Precursor Solution Water Ultrasonic transducer Liner source nozzle Substrate Stage and heater

Osaka Prefecture University, Japan

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Preparation of LiMn2O4 thin films by mist-CVD process Preparation of LiMn2O4 thin films by mist-CVD process

0.06M Mn(OCOCH3) 2.4H2O + 0.033M Li( OCOCH3)

Molar ratio (Li : Mn=1.1:2)

Heat-treated at 500-800oC for 1h Flow rates 8 L/min Substrate temperature 200- 400oC

Substrates

LiMn2O4 has advantages of low-cost, environmental friendliness, and high abundance.

LiMn2O4 thin films

Osaka Prefecture University, Japan

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LiMn2O4 thin films (substrate temperature: 200oC) LiMn2O4 thin films (substrate temperature: 200oC)

As prepared

10 20 30 40 50 60 70 80

After heat treatment at 700℃

Intensity( arb.unit

2 θ / o (CuKα)

750 nm 5 μm

As prepared by mist-CVD process After the heat treatment at 700oC 1 μm 750 nm

JCPDS LiMn2O4 Au/SiO2 substrate

Spinel type LiMn2O4 single-phase thin film was obtained.

Osaka Prefecture University, Japan

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Electrochemical behavior of heat-treated LiMn2O4 thin film Electrochemical behavior of heat-treated LiMn2O4 thin film

20 40 60 80 100 2.5 3 3.5 4 4.5

Capacity/mAhg-1

25 C, 0.05 mA cm-2

Cell voltage/V( Li+/Li)

1st~10th 1st~10th

beaker cell with three electrodes

W.E. LiMn2O4 Film

• R. E.

Li film C.E . Li film electrolyte 1 M LiPF6 (EC+DEC)

The LiMn2O4 thin-film electrode produced with the mist CVD method

• Capacity is 80 mAhg-1
• Good cycle performance

Osaka Prefecture University, Japan

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0.5 1 1.5 2 2.5 3 20 40 60 80 100 120

Charge-discharge behavior of Li4Ti5O12 thin films prepared by the mist-CVD Capacity / mAh g-1

25 ℃, 0.1 mA cm-2 Ceｌｌ potential vs . Li / V 10 th←1 st 1 st 10 th←2 nd

500 nm

Substrate temperature :400 oC + Heat-treatment at 700 oC for 1 h

[Li] = 0.02 M, [Ti] = 0.025 M Thick film with cracks showed good cycle performance. beaker cell with three electrodes

W.E. Li4Ti5O12 Film

• R. E.

Li film C.E . Li film electrolyte 1 M LiPF6 (EC+DEC)

Osaka Prefecture University, Japan

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Solid electrolyte for thin film battery

Li1.5Al0.5Ge1.5(PO4)3 (LAGP) electrolyte can be prepared with a rather low sintering temperature. Preparation of Li1.5Al0.5Ge1.5(PO4)3 thin films by mist-CVD process Preparation of Li1.5Al0.5Ge1.5(PO4)3 thin films by mist-CVD process Electrolyte thin films are formed on electrode thin films => low temperature synthesis is expected.

Osaka Prefecture University, Japan

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XRD pattern of the LAGP thin films

10 20 30 40 50 60 70 80

Sintering at 800oCfor 2 h Intensity( arb.unit As-prepared 2 θ/° (CuKα) LAGP Sintering at 700oCfor 2 h Sintering at 600oCfor 2 h ( Stage temperature:400 oC)

• Peaks due to LAGP were observed in

the as-prepared thin film.

• crystallinity increases with an

increase in heat treatment temperature.

• LAGP phase was obtained as

single-phase.

Osaka Prefecture University, Japan

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1000T-1K-1 Conductivity / S cm-1

2 2.5 3 3.5

Heat treatment temperature 600oC

Ionic conductivity of the LAGP thin film

Conductivity in room temperature : about 2x10-6 S cm-1 Activation energy of conduction : About 40 kJ mol-1

10-6 10-5 10-4 10-3

Osaka Prefecture University, Japan

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Osaka Prefecture University, Japan

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Osaka Prefecture University, Japan

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Conclusions Conclusions ・ LiMn2O4 cathode thin films, Li4Ti5O12 anode thin films, and Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid electrolyte thin films were prepared by the mist CVD process. ・ Li4Ti5O12 anode thin films were prepared by a sol-gel process. ・New lithium ion conductive inorganic-organic hybrid was developed.