Nano-structural changes in Li-ion battery cathodes during cycling revealed by FIB-SEM serial sectioning tomography

The growing demand for reliable, durable electrical energy systems to power electric and hybrid vehicles motivates worldwide efforts aimed at developing high-energy, high-power density batteries. One of the obstacles to widespread industry adoption is the lack of profound understanding and the ability to monitor and control the long-term degradation and capacity fading observed in these systems. Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM) serial sectioning is used to reconstruct the evolution of the three-dimensional structure of Li-ion battery electrodes during extended cycling. High resolution imaging reveals microstructural information at the level of the composite framework consisting of the spheroidal micro-particles of the active material held together by the polymer matrix. The evolution of damage within the micro-particles of the active material can be seen in the form of voiding, cracking and ultimate fragmentation. In particular, when spherical micro-particles of Li-rich layered oxides are used as the cathode, it is found that the extent of fragmentation varied in the direction of Li+ diffusion current from the particle surface inwards. We use a simple model of the strain and strain gradient effects of Li+ transient diffusion within the electrode to identify the driving force for particle fragmentation, and discuss the implication of these results.

[1]  Kim Seng Lee,et al.  NH4F surface modification of Li-rich layered cathode materials , 2014 .

[2]  Haoshen Zhou,et al.  Direct atomic-resolution observation of two phases in the Li(1.2)Mn(0.567)Ni(0.166)Co(0.067)O2 cathode material for lithium-ion batteries. , 2013, Angewandte Chemie.

[3]  Lisa C. Klein,et al.  Cobalt dissolution in LiCoO2-based non-aqueous rechargeable batteries , 1996 .

[4]  Ellen Ivers-Tiffée,et al.  Reconstruction of porous electrodes by FIB/SEM for detailed microstructure modeling , 2011 .

[5]  J. Shim,et al.  Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature , 2002 .

[6]  K. Amine,et al.  Nanostructured Lithium Nickel Manganese Oxides for Lithium-Ion Batteries , 2010 .

[7]  K. Amine,et al.  Nanoscale Phase Separation, Cation Ordering, and Surface Chemistry in Pristine Li1.2Ni0.2Mn0.6O2 for Li-Ion Batteries , 2013 .

[8]  Doron Aurbach,et al.  On the correlation between surface chemistry and performance of graphite negative electrodes for Li ion batteries , 1999 .

[9]  Marco Stampanoni,et al.  Visualization and Quantification of Electrochemical and Mechanical Degradation in Li Ion Batteries , 2013, Science.

[10]  Stephen J. Harris,et al.  Measurement of three-dimensional microstructure in a LiCoO2 positive electrode , 2011 .

[11]  J. Colin,et al.  First evidence of manganese-nickel segregation and densification upon cycling in Li-rich layered oxides for lithium batteries. , 2013, Nano letters.

[12]  Kang Xu,et al.  In situ and quantitative characterization of solid electrolyte interphases. , 2014, Nano letters.

[13]  Moses Ender,et al.  Three-dimensional reconstruction of a composite cathode for lithium-ion cells , 2011 .

[14]  Y. K. Chen-Wiegart,et al.  Three-dimensional morphological measurements of LiCoO2 and LiCoO2/Li(Ni1/3Mn1/3Co1/3)O2 lithium-ion battery cathodes , 2013 .

[15]  N. Otsu.  A threshold selection method from gray level histograms , 1979 .

[16]  Ji‐Guang Zhang,et al.  Corrosion/fragmentation of layered composite cathode and related capacity/voltage fading during cycling process. , 2013, Nano letters.

[17]  Manabu Watanabe,et al.  Cyclic deterioration and its improvement for Li-rich layered cathode material Li[Ni0.17Li0.2Co0.07Mn0.56]O2 , 2010 .

[18]  Li Lu,et al.  Influence of Ru substitution on Li-rich 0.55Li2MnO3·0.45LiNi1/3Co1/3Mn1/3O2 cathode for Li-ion batteries , 2012 .

[19]  Yang-Kook Sun,et al.  Mechanism of capacity fade of MCMB/Li1.1[Ni1/3Mn1/3Co1/3]0.9O2cell at elevated temperature and additives to improve its cycle life , 2011 .

[20]  Konstantin Mischaikow,et al.  Three-Dimensional Analysis of Solid Oxide Fuel Cell Ni-YSZ Anode Interconnectivity , 2009, Microscopy and Microanalysis.

[21]  T. Sui,et al.  Explicit formulae for the internal stress in spherical particles of active material within lithium ion battery cathodes during charging and discharging , 2015 .

[22]  Zhigang Suo,et al.  Large Plastic Deformation in High-Capacity Lithium-Ion Batteries Caused by Charge and Discharge , 2011 .

[23]  Li Lu,et al.  Structural evolution and the capacity fade mechanism upon long-term cycling in Li-rich cathode material. , 2012, Physical chemistry chemical physics : PCCP.

[24]  Gary M. Koenig,et al.  Composition-Tailored Synthesis of Gradient Transition Metal Precursor Particles for Lithium-Ion Battery Cathode Materials , 2011 .

[25]  Jianming Zheng,et al.  Formation of the spinel phase in the layered composite cathode used in Li-ion batteries. , 2012, ACS nano.

[26]  M. Balasubramanian,et al.  Designing High-Capacity, Lithium-Ion Cathodes Using X-ray Absorption Spectroscopy , 2011 .

[27]  Jon M. Hiller,et al.  Three-dimensional reconstruction of a solid-oxide fuel-cell anode , 2006, Nature materials.

[28]  Seung M. Oh,et al.  Degradation mechanisms in doped spinels of LiM0.05Mn1.95O4 (M=Li, B, Al, Co, and Ni) for Li secondary batteries , 2000 .

[29]  Jing Zhang,et al.  First Principles Study on the Electrochemical, Thermal and Mechanical Properties of LiCoO2 for Thin Film Rechargeable Battery , 2014 .