The effects of shear degradation on the microstructures and properties of grease were investigated using a planetary ball mill to simulate a bearing shear zone on grease. The microstructure, cone penetration, colloidal stability, rheological properties noise properties, water washout characteristics and low-temperature torque of lithium grease were characterized. The microstructure of the initial lithium grease is a three-dimensional network structure formed by the uniform fibers. The entanglement level is high. As the ball milling shear time increases, the network structure of lithium grease is destroyed and the fibers are sheared to become short. Eventually all of them become short fibers. The performance test of lithium grease reveal that the cone penetration increases, colloidal stability, structural strength, noise properties, water washout characteristics of lithium grease gradually decreased with the increase of ball milling shear time. Additionally, the low-temperature starting torque and running torque of the grease gradually decrease. This phenomenon occurs due to changes in the microstructure of lithium grease. The shear degradation of lithium grease was mainly divided into two stages: the rapid stage was the destruction of the thickener network structure and the fibers being shortened by shearing. The slow stage was the process in which short fibers were sheared into shorter fibers.
To achieve high energy density lithium-ion battery depends on high area load of the active material in the cathode. However, it is challenging to attain high loading of active material by traditional wet coating method due to large amount of organic solvent used. A solvent-free manufacturing cathode that take advantages of viscous flow polymer binder under shearing force of ball-milling to bind the active materials and the conductive carbon uniformly on the current collector is an environment-friendly alternative and has attracted increasing attention. Herein, a solvent free manufacturing LiFeO 4 cathode with thermoplastic polymer poly(lactide-co-propylene carbonate) as functional binder has high area loading up to 57 mg/cm 2 of active material, and the battery assembled with such a LiFeO 4 cathode and lithium metal anode can release a specific capacity of 135.5 mAh/g at 0.2C. In addition, the cathode using poly(propylene carbonate) or polycaprolactone functional binder can also be loaded with 40 mg/cm 2 of active material, which expands the variety of binders for solvent free manufacturing electrodes. Solvent free manufacturing electrodes with such functional binders are expected to break through the technical bottleneck of lithium-ion battery with high energy density.
危险品化学品经营许可证（带存储）