Characterization of advanced electrode materials by means of ion - - PowerPoint PPT Presentation

Characterization of advanced electrode materials by means of ion beam analysis technique for next generation Li-ion batteries

Spanish leader

• Prof. J. Manuel Perlado Martin

Japanish leader

• Prof. Yoshiaki Kato

Outline

• Motivation.
• Ion Beam Analysis Techniques for Li characterization.
• Experimental results on Li distribution characterization in Li-ion batteries

positive electrodes containing LixNi0.8Co0.15Al0.05O2 secondary particles (1.0≤x≤0.5).

• Experimental results on Li depth profiling in LiFeP.
• Conclusions.

Motivation

Motivation

Further development of Li-ion batteries requires Li characterization.

• Li-ion batteries consist of a positive and a negative electrode separated by an

electrolyte layer. When electrodes are linked by an external circuit, spontaneous electrochemical reactions, which involve Li diffusion, take place.

• Therefore, the performance of a Li-ion battery (energy density, power, capacity,

charge and discharge rates and lifetime) strongly depends, among other factors,

• n the characteristic of the electrodes and in particular on the Li diffusion

capabilities on them.

Available techniques for Li‐ion batteries characterization

Li characterization

Two remaining questions:

• Can we measure the Li concentration?
• If so, can we measure it during the charge-discharge

processes?

Li characterization

• TEM and EELS are techniques with surface sensitivity ”can

not be applied to real electrodes”.

• No quantitative information

The Electrochemical Society Interface • Fall 2011

Charge and discharge processes

Interest in the Li movement Can we measuring the batteries microstructure and composition during the charge-discharge processes? YES, ….. BUT

In-situ XRD diffraction of C- LiFe0.6Mn0.4PO4 during the first charge-discharge cycle. Detailed structure of the XRD pattern during the first charging process.

From XRD measurements only information about the crystalline phases can be obtained Is the Li always present in crystalline phases?

Ion Beam Analysis tecniques (IBA)

Courtesy of Dr. F. Munnik

Iman conmutador

Analysis- magnet

Scattered Ions Electrons X-rays Nuclear reaction Products γ - rays Recoil ions

Target Ion lens

RBS NRA PIGE PIXE ERDA

ion source

MeV-Ion-Accelerator

IBA for Li characterization

Characterize the Li distribution by means of

• PIGE spatial characterization
• NRA depth profiling

Advantages:

• Quantitative information about the elemental distribution.
• Simultaneous measurement of different elements.
• PIXE, PIGE and NRA spectra can be simultaneously measured.
• The use of micro-beams allow good spatial resolution.
• The use of external micro-beams allow measure large samples.
• The use of NRA allow measuring the Li depth profiling without destroying

samples.

3/14/2013

IBA for Li characterization: necessity for cooperation

CMAM/UAM SPAIN CNA/US JAPAN TIARA/JAEA

Li distribution characterization in positive electrodes containing LixNi0.8Co0.15Al0.05O2 secondary particles (1.0≤x≤0.5)

Objectives

• Characterize

the elemental distribution in Li-ion battery positive electrodes containing LixNi0.8Co0.15Al0.05O2 (1.0≤x≤0.5) microparticles:

• As received (non-charged)
• Charged
• Study the dependence of the Li

distribution on:

• Electrode thickness.
• Charging conditions.

For these aims, cross-sectional samples need to be fabricated

As-received electrode

As-received individual microparticles

• Li-rich

and Li-depleted regions

• μ-particles

distribution.

• The

Li distribution is homogeneous within the individual μ-particles.

• K. Mima et al. NIMB 290 (2012) 79

Li distribution characterization in positive electrodes containing LixNi0.8Co0.15Al0.05O2 secondary particles (1.0≤x≤0.5)

We thank the team of TOYOTA for supplying and preparation of the samples as well as, for the very nice cooperation.

• One

single measurements gives information about the constituents of

• Active material: Ni, Co,

Al..

• Binder: F, O, ..
• Li yield is higher for the

uncharged than for the charged electrode.

• The Ni yield is the same in

both electrode.

• Li/NiAR~1.10
• Li/NiCh~0.94
• K. Mima et al. NIMB 290 (2012) 79

Li distribution characterization in positive electrodes containing LixNi0.8Co0.15Al0.05O2 secondary particles (1.0≤x≤0.5)

The Li distribution is more homogeneous for the thin than for the thick electrode.

Thickness dependence: Th= 105 μm Th= 35 μm

Th (μm) dc (mA/c m2) t (min)

35 2 15 105 6 15

Li distribution characterization in positive electrodes containing LixNi0.8Co0.15Al0.05O2 secondary particles (1.0≤x≤0.5)

• K. Mima et al. NIMB 290 (2012) 79

• Li inhomogeneously distributes in both electrodes
• Fast charge → Homogeneous gradient in the Li distribution
• Slow charge→ Two regions with an abrupt boundary between them.

Charge rate dependence:

6m A/cm2 15 min. 0.6 mA/cm2 150 min.

• K. Mima et al. NIMB 290 (2012) 79

Li distribution characterization in positive electrodes containing LixNi0.8Co0.15Al0.05O2 secondary particles (1.0≤x≤0.5)

• μ-PIGE and μ-PIXE techniques are successfully applied to accurately measure

the elemental (in particular Li) distribution in Li-ion batteries.

• Li inhomogenously distributes in the electrode

to the random distribution of the secondary particles.

• The Li distribution within as-received individual secondary particles turns out

to be homogeneous.

• The Li distribution in the cross sections of the electrodes is observed to depend
• n electrode thickness and on charge conditions.
• The Li distribution is:
• Homogeneous in a thin electrode (35 μm),
• Inhomogeneous when increasing the thickness (105 μm).
• For the thick electrode (105μm) slow charge rate gives rise to a small gradient of

the Li distribution in the electrode regions close to the Al current collector.

CONCLUSIONS

CONCLUSIONS

Answer to questions:

• Can we measure the Li concentration?
• Yes, we can.
• Can we measure it during the charge-discharge

processes?

• For the time being we have demonstrated that it can be

measured in charged and uncharged batteries.

Manpower

• Prof. José Manuel Perlado
• Prof. Emilio Minguez
• Dr. Jesús Álvarez
• Assoc. Prof. Emma del Río
• Assoc. Prof. Raquel Gonzalez‐

Arrabal

• Assoc. Prof. Antonio Rivera

Miguel Panizo

• Prof. Yoshiaki Kato (GPI)
• Prof. Kunioki Mima (GPI)
• Prof. Sadao Nakai (GPI)
• Assoc. Prof. Kazuhisa Fujita (GPI)
• Prof. Yoshiharu Uchimoto (Kyoto

University)

• Dr. Hirozumi Azuma (TCRL)
• Dr. Yoshio Ukyo (TCRL)
• Prof. Hiroaki Nishimura (ILE)
• Prof. Tomihiro Kamiya (TIARA)