Stability of Slip Flow in Microbearings

Volume Deformation of Large-Format Lithium Ion Batteries under Different Degradation Paths

“…To be specific, Peak I at 3.4 V and Peak III at 3.7 V were related to the phase transformation processes of the graphite anode, whereas Peak IV at 4.1 V corresponds to the phase transformation process of the NCM111 cathode. 31,33 Peak II at 3.59 V can be ascribed to a combination of both the graphite anode and the NCM111 cathode. 33 For batteries cycled at −5°C/1 C (Fig.…”

“…31,33 Peak II at 3.59 V can be ascribed to a combination of both the graphite anode and the NCM111 cathode. 33 For batteries cycled at −5°C/1 C (Fig. 4a), Peak II drops much more significantly than other peaks.…”

“…12,14,25,30 Battery degradation can originate from loss of lithium inventory (LLI), loss of active material (LAM), and increased internal resistance (IIR). [31][32][33] LLI can be induced by repeated cracking and thickening of SEI films, lithium plating under high rate cycling, or low temperature cycling. 4,12 LAM on the cathode can result from side reaction between cathode and electrolyte, lattice oxygen release, transition metal dissolution, chemo-mechanical breakdown, and phase transformation.…”

“…4,6,35 The degradation mechanism of lithium ion batteries can be analyzed noninvasively through the cyclic voltammetry (CV), incremental capacity analysis (ICA), and differential voltage (DV) methods. [31][32][33]36 This study analyzes the mechanisms of reversible and irreversible deformation of large-format lithium ion batteries under different degradation paths. A commercial large-format pouch battery is used for the degradation test with four paths including cycling at −5°C/1 C, 55°C/1 C and 25°C/4 C, and storage at 55°C/100% SOC.…”

Combined Effect of Rarefaction and Effective Viscosity on Micro-Elasto-Aerodynamic Lubrication Performance of Gas Microbearings

“…For applications involving micro-electromechanical systems (MEMS) microfluidic devices with high power efficiency and density, such as micro gas turbines, microgenerators, micromotors, medical devices, and hard disk drives (HDDs), there has been great interest in micro gas journal bearings. Previous investigations show that self-acting gas bearings offer certain advantages over the rolling element bearings, magnetic bearings, and oil/water-lubricated bearings including simpler structure design, higher precision, lower power loss, lower frictional characteristics, no contamination due to leakage of lubricants and lesser restrictions on speed and temperature [1,2,3,4,5]. In the conventional bearing design of hydrodynamic lubrication, it has been assumed that the bearing shell is rigid and the lubricant viscosity is constant.…”