Effect of LiCoO₂Cathode Density and Thickness on Electrochemical Performance of Lithium-Ion Batteries

Abstract

ABSTRACT:The consequences of electrode density and thickness for electrochemical performance of lithiumion cells are investigated using 2032-type coin half cells. While the cathode composition is maintained by 90:5:5 (wt.%) with LiCoO 2 active material, Super-P electric conductor and polyvinylidene fluoride polymeric binder, its density and thickness are independently controlled to 20, 35, 50 um and 1.5, 2.0, 2.5, 3.0, 3.5 g cm , respectively, which are based on commercial lithium-ion battery cathode system. As the cathode thickness is increased in all densities, the rate capability and cycle life of lithium-ion cells become significantly worse. On the other hand, even though the cathode density shows similar behavior, its effect is not as high as the thickness in our experimental range. This trend is also investigated by cross-sectional morphology, porosity and electric conductivity of cathodes with different densities and thicknesses. This work suggests that the electrode density and thickness should be chosen properly and mentioned in detail in any kinds of research works.

Quantifying the Dependence of Battery Rate Performance on Electrode Thickness

“…6 However, as mentioned above, increasing thickness also results in a reduction in R T and hence a degradation of rate performance. 3,5,9,10 The combination of these effects means that while thin electrodes display low absolute capacity but excellent rate performance, thick electrodes display high absolute capacity only at a low rate. As a result, there is a trade-off between maximization of capacity and rate performance 4 that is not always fully appreciated.…”

Three-Dimensional Adhesion Map Based on Surface and Interfacial Cutting Analysis System for Predicting Adhesion Properties of Composite Electrodes

“…Alternatively, battery manufacturers have improved the volumetric energy density and gravimetric energy density of the batteries through a practical approach, i.e., the cell design optimization of LIBs, including electrode thickness, electrode density, porosity, and active material particle size. These are known to be important to utilize the full potential of the active materials. − For example, increasing the thickness of the electrodes cannot only minimize the relative volume and weight of the inactive components (separators and current collectors) but also reduce cell-manufacturing costs owing to fewer cutting and stapling steps. , …”

Electrochemical Cycle-Life Characterization of High Energy Lithium-Ion Cells with Thick Li(Ni0.6Mn0.2Co0.2)O2and Graphite Electrodes

“…There are two ways to improve the energy density of Li-ion batteries: improve and utilize high-capacity electrode materials, such as Ni-rich Li(Ni x Mn y Co z )O 2 (NMC) (x+y+z = 1, x≥0.5) layered oxides [2][3][4][5] and Li-rich layered oxides 6,7 used as positive electrode materials, Si-based composites 4,6 and Li metal 8,9 used as negative electrode materials; and increase the portion of active electrode materials contributing to the cell energy while minimizing the portion of non-active components, such as separators and current collecting foils, through optimization of cell design. [10][11][12] In the latter category, high active material loading or thick electrode is a major direction. In the present paper, Li-ion batteries with thick graphite anodes and thick Ni-rich NMC cathodes will be explored for near-term EV batteries.…”