title: Intragranular cracking as a critical barrier for high-voltage usage of layer-structured cathode for lithium-ion batteries.
abstract: LiNi1/3Mn1/3Co1/3O2-layered cathode is often fabricated in the form of secondary particles, consisting of densely packed primary particles. This offers advantages for high energy density and alleviation of cathode side reactions/corrosions, but introduces drawbacks such as intergranular cracking. Here, we report unexpected observations on the nucleation and growth of intragranular cracks in a commercial LiNi1/3Mn1/3Co1/3O2cathode by using advanced scanning transmission electron microscopy. We find the formation of the intragranular cracks is directly associated with high-voltage cycling, an electrochemically driven and diffusion-controlled process. The intragranular cracks are noticed to be characteristically initiated from the grain interior, a consequence of a dislocation-based crack incubation mechanism. This observation is in sharp contrast with general theoretical models, predicting the initiation of intragranular cracks from grain boundaries or particle surfaces. Our study emphasizes that maintaining structural stability is the key step towards high-voltage operation of layered-cathode materials.
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, USA.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Yan
authors.affiliation: Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, USA.
authors.forename: Jianming
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, USA.
authors.forename: Meng
authors.initials: M
authors.lastname: Gu
authors.affiliation: Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, USA.
authors.forename: Ji-Guang
authors.identifier: 0000-0001-7343-4609
authors.initials: JG
authors.lastname: Zhang
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, USA.
authors.forename: Chong-Min
authors.initials: CM
authors.lastname: Wang