Structural Effect of Conductive Carbons on the Adhesion and Electrochemical Behavior of LiNi0.4Mn0.4Co0.2O2 Cathode for Lithium Ion Batteries

Abstract

The adhesion strength as well as the electrochemical properties of LiNi

Choosing Carbon Conductive Additives for NMC-LATP Composite Cathodes: Impact on Thermal Stability

“…3c) confirm that in all cases the expected redox processes occur in NMC (hexagonal H1 ↔ monoclinic M around 3.7 V). [39][40][41][42][43][44] The electrochemical performance of heat-treated composites reveals that the heat treatment significantly alters the composite electrochemical performance with all grades of carbons. Figure 3d shows the second charge-discharge curve of the heated composites at C/20, where it can be observed that 500-KB composite has a significant drop in capacity (more than 20%) along with an enhanced polarization and a more slopy discharge curve compared to the corresponding mixed composite.…”

Effect of Single-Walled Carbon Nanotube Sub-carbon Additives and Graphene Oxide Coating for Enhancing the 5 V LiNi0.5Mn1.5O4 Cathode Material Performance in Lithium-Ion Batteries

“…Figure S2 displays the surface morphologies of the SWCNTs (sub-carbon additive) and GO nanosheets (coating material). The SEM image of the as-received SWCNTs (Figure S2A) reveals a long fibrous (nanowire-like) morphology with a smooth surface, potentially effective for conducting electrons over a wide range due to the ordered graphitic planes of the CNT network. , The SEM image of the as-received GO nanosheets reveals a multilayer structure (Figure S2B); they further exfoliated into transparent GO nanosheets with a few layers (see the TEM image in Figure S2C) upon dilution of the as-received GO solution and subsequent ultrasonication. These two-dimensional (2D) GO nanosheets would presumably form a strong and thin protective layer on the LNMO surface, stabilized through electrostatic or hydrogen bonding interactions. , Figure C,D presents SEM images of the pristine LNMO and 0.1%SWCNT-LNMO electrodes.…”

“…Conductive carbon additives used in electrode fabrication have also played another vital role: enhancing the electronic conductivity of the active materials in LIBs. − Most carbon materials, including acetylene black, super P, Ketjen black, graphite, carbon nanotubes (CNTs), and vapor-grown carbon fibers (VGCFs), have been explored as conductive additives in the preparation of LIB electrodes due to their excellent electronic conductivities and thermal stabilities. , These conductive additives tend to wrap up the grains of the active materials and induce uniform charge distribution to decrease the contact and internal resistances of the electrodes, thereby improving the high-rate performance. Nevertheless, the feature sizes and morphologies of these conductive additives can affect the adhesion and electrochemical performance of the high-voltage cathode materials.…”

“…The conductive additives listed above can be classified into two categories: particle-like (acetylene black, super P, Ketjen black, graphite) and fiber-like (CNTs and VGCFs). The particle-like additives can readily fill the spaces between the secondary particles; the fiber-like structures can form bridges between adjacent particles over long distances and connect them electronically over a broader space . Lin et al found, however, that carbon additives with smaller particle sizes (Ketjen black < super P or acetylene black) increased the discharge capacities of spinel cathode materials (LiMn 2 O 4 and LiNi 0.5 Mn 1.5 O 4 ) while also enhancing electrolyte decomposition due to the large specific surface area, thereby decreasing the Coulombic efficiency.…”

“…The particle-like additives can readily fill the spaces between the secondary particles; the fiber-like structures can form bridges between adjacent particles over long distances and connect them electronically over a broader space. 44 Lin et al 43 found, however, that carbon additives with smaller particle sizes (Ketjen black < super P or acetylene black) increased the discharge capacities of spinel cathode materials (LiMn 2 O 4 and LiNi 0.5 Mn 1.5 O 4 ) while also enhancing electrolyte decomposition due to the large specific surface area, thereby decreasing the Coulombic efficiency. In contrast, the electrical resistance obtained when using fiber-like CNTs was less than that obtained with VGCFs due to the ordered graphitic nature of CNTs allowing excellent electronic conductivity over the fiber structure.…”