title: Visualizing the chemistry and structure dynamics in lithium-ion batteries by in-situ neutron diffraction.
abstract: We report an in-situ neutron diffraction study of a large format pouch battery cell. The succession of Li-Graphite intercalation phases was fully captured under an 1C charge-discharge condition (i.e., charge to full capacity in 1 hour). However, the lithiation and dilithiation pathways are distinctively different and, unlike in slowing charging experiments with which the Li-Graphite phase diagram was established, no LiC₂₄ phase was found during charge at 1C rate. Approximately 75 mol. % of the graphite converts to LiC₆ at full charge, and a lattice dilation as large as 4% was observed during a charge-discharge cycle. Our work demonstrates the potential of in-situ, time and spatially resolved neutron diffraction study of the dynamic chemical and structural changes in "real-world" batteries under realistic cycling conditions, which should provide microscopic insights on degradation and the important role of diffusion kinetics in energy storage materials.
authors.affiliation: Chemical and Engineering Materials Division, Oak Ridge National Laboratory Oak Ridge, TN 37831-6465, USA. xlwang@cityu.edu.hk
authors.forename: Xun-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Ke
authors.initials: K
authors.lastname: An
authors.forename: Lu
authors.initials: L
authors.lastname: Cai
authors.forename: Zhili
authors.initials: Z
authors.lastname: Feng
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Nagler
authors.forename: Claus
authors.initials: C
authors.lastname: Daniel
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Rhodes
authors.forename: Alexandru D
authors.initials: AD
authors.lastname: Stoica
authors.forename: Harley D
authors.initials: HD
authors.lastname: Skorpenske
authors.forename: Chengdu
authors.initials: C
authors.lastname: Liang
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Joon
authors.initials: J
authors.lastname: Kim
authors.forename: Yue
authors.initials: Y
authors.lastname: Qi
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Harris
mesh_terms: D011211:Electric Power Supplies; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D033363:Neutron Diffraction
chemical_list: D007477:Ions; D006108:Graphite; D008094:Lithium