Stabilization of a High-Capacity and High-Power Nickel-Based Cathode for Li-Ion Batteries  Xiaoqiao Zeng, Chun Zhan, Jun Lu, Khalil Amine  Chem  Volume 4, Issue 4, Pages 690-704 (April 2018) DOI: 10.1016/j.chempr.2017.12.027 Copyright © 2018 Elsevier Inc. Terms and Conditions

Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 1 Lattice Structure and Activation Barrier of Lithium Transition-Metal Oxide (A) The structure of Li(Ni0.5Mn0.5)O2 consists of layers of transition metal (Ni and Mn) separated from Li layers by oxygen. In materials made by conventional high-temperature synthesis, partial exchange of Li and Ni ions is always observed, which contracts the space through which Li can move. (B) Li moves from one octahedral site to another by passing through an intermediate tetrahedral site where it encounters strong repulsion from a nearby transition-metal cation. The table shows the activation barrier for Li motion for various transition metals near the activated state. Values were calculated by gradient-corrected approximation density functional theory for various chemistries and Li contents. From Kang et al.9 Reprinted with permission from AAAS. Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 2 Typical Synthesis Process of Co-precipitated Surface Coating on a Pristine Cathode Particle Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 3 Functions of AlF3 Surface Coating (A) TEM image of primary particles from a 5 wt % AlF3-coated sample that was completely encapsulated by the AlF3 coating. (B) Differential scanning calorimetry (DSC) trace of pristine and AlF3-coated electrodes charged to 4.6 V. Adapted with permission from Sun et al.103 Copyright 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 4 Typical Synthesis Process of a Microscale Spherical Core-Shell Particle Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 5 SEM Cross-sectional Images of the Core-Shell Structure [Ni0.8Co0.1Mn0.1](OH)2 encapsulated by [Ni0.5Mn0.5](OH)2 for (A) 20 min, (C) 40 min, (D) 2 hr, (E) 3 hr, and (F) 4 hr; (G) core Li[Ni0.8Co0.1Mn0.1]O2; (H) thermally lithiated product of (B); (I) lithiated product of (C); (J) lithiated product of (D); (K) lithiated product of (E); and (L) lithiated product of (F). The white arrows indicate the interfaces of core and shell regions. Scale bars represent 4 μm. Adapted with permission from Sun et al.109 Copyright 2006 American Chemical Society. Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 6 SEM and Electron-Probe X-Ray Microanalysis of the Core-Shell Structure SEM photograph (A) and EPMA line scan (B) of precursor hydroxide and SEM photograph (C) and EPMA line scan (D) of the final lithiated oxide Li[Ni0.64Co0.18Mn0.18]O2. In both cases, the gradual concentration changes of Ni, Mn, and Co in the interlayer are clearly evident. The Ni concentration decreases and the Co and Mn concentrations increase toward the surface. Adapted by permission from Springer Customer Service Centre GmbH: Springer Nature, Nature Materials Sun et al.,111 copyright 2009. Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 7 Typical Synthesis Process of a Full Concentration Gradient Particle Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 8 Schematic Diagram of the FCG Lithium Transition-Metal Oxide Particle with a Decreasing Nickel Concentration from the Center toward the Outer Layer and a Corresponding Increasing Concentration of Manganese SEM mapping photograph of Ni, Co, and Mn within a single particle for the precursor (A) and for the lithiated material (B). EPMA line scan of the integrated atomic ratio of transition metals is shown as a function of the distance from the particle center to the surface for the precursor (C) and the lithiated material (D). The Ni-rich particle center and Mn-rich outer surface are clearly seen from the SEM mapping images. The Ni concentration decreased linearly toward the particle surface for both the precursor and the lithiated particle, whereas the Mn concentration increased, and the Co concentration remained constant. Adapted by permission from Springer Customer Service Centre GmbH: Springer Nature, Nature Materials Sun et al.,107 copyright 2012. Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 9 Hard X-Ray Nanotomography and TEM Images (A) X-ray nanocomputed tomography image of the 3D distribution of nickel concentration in a single lithiated FCG lithium transition-metal oxide particle. (B) 2D distribution of nickel on a plane going through the center of the particle. The high nickel content regions shown as bright areas tend to form needle-shaped spikes radiating outwards from a ∼2 μm central core. (C) TEM image of the local structural feature near the edge of the particle shows highly aligned nanorods. (D) TEM image of the local structural feature at the center of the particle shows that an aligned nanorod network at the particle center was not developed. Adapted by permission from Springer Customer Service Centre GmbH: Springer Nature, Nature Materials Sun et al.,107 copyright 2012. Chem 2018 4, 690-704DOI: (10.1016/j.chempr.2017.12.027) Copyright © 2018 Elsevier Inc. Terms and Conditions