Development of Non-Fluorinated Cathodes Based on Li₃V_1.95Ni_0.05(PO₄)₃/C with Prolonged Cycle Life: A Comparison among Na-Alginate, Na-Carboxymethyl Cellulose and Poly(acrylic acid) Binders

Abstract

Non-fluorinated Li3V1.95Ni0.05(PO4)3/C-based electrodes were prepared by using sodium carboxymethyl cellulose, sodium alginate and poly(acrylic acid) as alternative binders of the standard poly(vinylidene difluoride). The effect of the binders was investigated on several aspects, starting from the rheological properties of the dispersions, to the physical-chemical properties of the layers (adhesion test, electrode porosity, surface conductivity). The prepared Li3V1.95Ni0.05(PO4)3/C-based electrodes were characterized as cathodes at different C-rates ranging from 1 C to 200 C in two different potential windows, between 3.0–4.3 and 3.0–4.8 V vs. Li/Li+. The cycle life of the LVNP/C-based electrodes was characterized for each potential window at C-rate as high as 100 C and for 10000 cycles. Electrochemical impedance spectroscopy, scanning electrode microscopy, X-ray diffraction and energy dispersive X-ray measurements were used to study the aged electrodes. Among the electrodes, the one prepared with Na-alginate binder displays the best electrochemical performance, with a specific capacity of 100 and 85 mAh g−1 delivered at 100 C when charged up to 4.3 and 4.8 V vs. Li/Li+, respectively. Moreover, in the same potential windows, it displays an excellent cycling stability over 10000 cycles at 100 C, with a capacity retention of 80% and 65%

Production Research as Key Factor for Successful Establishment of Battery Production on the Example of Large‐Scale Automotive Cells Containing Nickel‐Rich LiNi0.8Mn0.1Co0.1O2 Electrodes

“…As shown in Figure , the viscosity rapidly decreases with increased shear rate, and the original viscosity is reached again in the recovery zone within a sufficiently short time of 5 s for the NMC811_A 15 h slurry and 11 s for the NMC622_A 15 h slurry. This fast regaining of the steady state demonstrates the excellent processability of the slurries and allows for the production of homogeneous, load gradient‐free electrodes with sharp edges, as the undesired flowing behavior as soon as the slurry passes the slot‐die can be considered as negligible …”

Influence of the Molecular Weight of Poly‐Acrylic Acid Binder on Performance of Si‐Alloy/Graphite Composite Anodes for Lithium‐Ion Batteries

“…The thixotropic behavior of the slurries was evaluated by using 3‐interval time test. Initially low shear rate was applied, which simulates the slow mixing in the vessel . At such slow shear rate all slurries showed relatively constant viscosity (some increase due to water evaporation could not be prevented).…”

“…Initially low shear rate was applied, which simulates the slow mixing in the vessel. [19] At such slow shear rate all slurries showed relatively constant viscosity (some increase due to water evaporation could not be prevented). A high stress was then applied for a short interval of time, which resembles the shear applied during the casting process.…”

Surface double coating of a LiNiaCobAl1−a−bO2(a> 0.85) cathode with TiOxand Li2CO3to apply a water-based hybrid polymer binder to Li-ion batteries

“…In recent years, water-soluble and aqueous polymer binders, i.e., water-based polymer binders, have become of great interest as alternatives to the poly(vinylidene diuoride) (PVdF) binder dissolved in N-methyl-2-pyrrolidone (NMP) for the cathodes of lithium ion batteries (LIBs) from the viewpoints of environmentally friendly electrode fabrication processes and reducing the cost of LIBs. [1][2][3][4][5][6][7][8][9][10][11][12][13] However, cathode materials such as LiNi 0.5 Mn 1.5 O 4 , 11 LiNi a Co b Al 1ÀaÀb O 2 (NCA) 12 and Li-rich solidsolution layered cathodes, 13 which are promising candidates as next generation positive-electrode active materials with high energy density for LIBs, are not stable in water-based slurry solutions because they contain a small amount of alkaline species such as LiOH as aresidue in their production process 14 and when they are dispersed in a water-based coating slurry, their surfaces are dissolved and its pH is increased, resulting in the corrosion of the Al foil current collectors and the falling off of active cathode materials from the current collector surfaces. 12 To prevent such a damage of cathode materials some ways have been proposed including the use of buffer agents to inhibit the increase in pH in the water-based slurry 15 and a stainless steel foil current collector 16 and the surface coating of cathode materials by carbon, 11 metal oxides 12 and Li 2 CO 3 .…”