A Paradigm of Calendaring‐Driven Electrode Microstructure for Balanced Battery Energy Density and Power Density

Abstract

The microstructure of an electrode plays a critical role in the electrochemical performance of lithium‐ion batteries, including the energy and power density. Using a micrometer‐scale Wadsley–Roth phase TiNb2O7 active material with Li intercalation chemistry as a model system, the relationship between electrochemical performance and microstructure of calendared electrodes with same mass loading but different electrode parameters is studied by both experimental investigation and theoretical modeling, providing a paradigm of calendaring‐driven electrode microstructure for balanced battery energy density and power density. Along with the reduction in porosity, ion and electron diffusion distance decreases, which is beneficial for charge transfer and rate capability. Nevertheless, the narrowed ion diffusion pathway increases the resistance for ion diffusion. The rate capability, volumetric capacity, and materials utilization are thus predominantly restricted by the microstructures of the electrode, providing fundamental insights into electrode microstructure design for different applications. As an example, an optimized TiNb2O7 electrode with compaction density of ≈2.5 g cm‐3 and mass loading of ≈8.5 mg cm‐2 provides the highest specific charge capacity of 271.3 mAh g‐1 at 0.2 C in half cell configuration and 70.4% capacity retention at 6 C in full configuration, enabling balanced energy density and power density of batteries.

The significance of mitigating crosstalk in lithium-ion batteries: a review

“…141,158 In view of the complexities of battery structure and components, a multiscale theoretical model based on molecular dynamics simulations, multiphysics field simulations, and machine learning techniques will be helpful for better probing crosstalk mechanisms. [159][160][161] In addition, the flexible use of reference electrodes (three-electrode or fourelectrode cells) will provide much convenience when studying the effects of crosstalk on battery behaviors. 21,27 (ii) Designing highly effective crosstalk mitigation strategies.…”

Through-hole graphite made from waste graphite for high-rate lithium-ion battery anodes

“…31,33 In addition, the Li-ion diffusion capacity of NFG and MDSG-480 are estimated by using the CV curves at the range of 0.1–1.0 mV s −1 . Their relationship is indicated by the following formula: 52 i p = 2.69 × 10 2 z 3/2 D 1/2 v 1/2 c where i p , z , D , v , and c correspond to the peak current density, number of exchange electrons, diffusion coefficient, sweep velocity, and concentration, respectively. The D of MDSG-480 at 1 mV s −1 is 1.23 times that of NFG (Fig.…”

Designing High‐mass Loading 2D Ni‐TiO2/graphene Pellet Electrodes for Lithium Metal Batteries

“…Traditionally, calendering can improve the volume energy density of the electrode, the contact between active particles, and the adhesion between the electrode and the current collector for the conventional slurry preparation process. [40,41] However, excessive calendering force during the calendering process will decrease porosity and increase the tortuosity of the electrode, which will negatively impact battery performance. [42] Therefore, we use pelleting instead of traditional calendering and add a pore-forming agent into the electrode mixture to realize the construction of porous channels.…”