Confronting Issues of the Practical Implementation of Si Anode in High-Energy Lithium- Ion Batteries  Sujong Chae, Minseong Ko, Kyungho Kim, Kihong Ahn, Jaephil Cho  Joule  Volume 1, Issue 1, Pages 47-60 (September 2017) DOI: 10.1016/j.joule.2017.07.006 Copyright © 2017 Elsevier Inc. Terms and Conditions

Joule 2017 1, 47-60DOI: (10.1016/j.joule.2017.07.006) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 1 Overview of the Challenges and Representative Strategies Associated with the Si Anode (A) Intrinsic properties of Si disadvantageous to charge transfer kinetics and stable cycling behavior. (B) Unfavorable phenomena in the Si anode causing the active material loss and consumption of lithium ion in the cell. (C) Various representative strategies for addressing the unfavorable phenomena such as size control, surface coating, active/inactive alloy, void space engineering, and composite. Joule 2017 1, 47-60DOI: (10.1016/j.joule.2017.07.006) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 2 Flow Chart of the Electrochemical Cell Design The brief procedure of the electrochemical cell design is presented from the customer demand, such as cell dimension and structure, to the full-cell assembly/evaluation. Joule 2017 1, 47-60DOI: (10.1016/j.joule.2017.07.006) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 3 Relationship between Energy Density and Electrode Swelling and the Measurement of Electrode Swelling (A) Energy density plot of Graphite/HVLCO and graphite-blended Si anode/HVLCO full cells as a function of the electrode swelling. (B) The limits of electrode swelling in different specific capacities of graphite-blended Si anode where the energy density of graphite-blended Si anode and graphite become the same. The electrode swelling of graphite is set as 20%. (C) Electrode porosity versus electrode density in graphite. The electrode porosity is estimated with the true density of graphite, binder, and conductive agents. (D) Ex situ measurement of the electrode swelling by micrometer and microscope. (E) In situ measurement of the electrode swelling with electrochemical dilatometry. Joule 2017 1, 47-60DOI: (10.1016/j.joule.2017.07.006) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 4 Causes of the Difference in Capacity Fading between the Half Cell and the Full Cell (A) Contrasting lithium sources in the half cell and in the full cell. The cyclable lithium is infinitely supplied from the lithium metal in the half cell, whereas the supply is limited to the capacity of the cathode in the full cell. (B) Different voltage behaviors between the half cell and the full cell. While the cutoff voltages and SOC are fixed with the lithium metal reference/counter electrode, the cutoff voltages and SOC shift as a result of the degradation. (C) The difference in the amounts of the electrolyte for the coin-type half cell and for the commercial full cell such as a pouch-type cell. The coin-type cell for the half-cell test is generally filled with the excessive amount of the electrolyte; on the other hand, the commercial cell such as pouch-type cell contains the limited amount of the electrolyte. Joule 2017 1, 47-60DOI: (10.1016/j.joule.2017.07.006) Copyright © 2017 Elsevier Inc. Terms and Conditions