High Volumetric Energy Density of LiFePO₄ Battery Based on Ultrasonic Vibration Combined with Thermal Drying Process

Abstract

Increasing the compaction density of electrodes is an effective way to increase the volumetric energy density of the full battery. To avoid the problem of low compaction density, material breakage, and porosity decrease during the process of calendering, which greatly deteriorate the electrochemical performance of the battery, in this paper, for the first time, we use ultrasonic vibrationassisted densification technology combining with thermal drying technology to prepare the electrodes. Ultrasonic vibration reduces the friction among the powder particles during the drying process, so that the particles of active materials could aggregate more closely. And then, there are smaller displacements and sliding during the calendering process in ultrasonic vibration-assisted (UV-A) electrode than ordinary ones, which not only avoid the failure of the binder and the shedding of the carbon layer, also increase the number of connection points between material particles. The results show that the UV-A densification technology leads to improved volumetric energy density (increased by 5.3%, 6.6%, 7.6%, 11.6%, 13.4%, and 13.0% compared to the ordinary battery at 0.2C, 0.5C, 1C, 2C, 5C, and 10C, respectively), cycle performance and ion conductivity of full battery.

Investigating the Microscopic Mechanism of Ultrasonic-Vibration-Assisted-Pressing of WC-Co Powder by Simulation

“…Here, under conventional pressing conditions, the friction coefficient of WC-Co is 0.2. Under ultrasonic pressing conditions, due to the anti-friction effect of ultrasound, the friction coefficient will be reduced by about 50%, according to Siegert’s research [ 18 , 19 , 20 ], so the friction coefficient is 0.1.…”

Microscopic Mechanism of Ultrosonic Vibration Assisted Pressing WC-Co Powder by Simulation

“…Here, under conventional pressing conditions, the friction coefficient of WC-Co is 0.2. Under ultrasonic pressing conditions, due to the anti-friction effect of ultrasound, the friction coefficient will be reduced by about 50% according to Siegert's research [16][17][18], so the friction coefficient is 0.1.…”

High Energy Density Large Particle LiFePO4

“…1 However, the mass application of LIBs, especially in the latter two applications, requires reductions in cost and environmental impact and improved sustainability. 1,2 The cathode materials used in LIBs contribute significantly to these factors. This is because the majority of Liion batteries utilize layered LiMO 2 oxide cathode materials, where M = Co (LCO), a mixture of Ni, Mn, and Co (NMC), or a mixture of Ni, Co, and Al (NCA).…”

“…Li-ion batteries (LIBs) have high gravimetric and volumetric energy density and moderate cost, making them the most widely used secondary battery chemistry in consumer electronics, electric vehicles (EVs), and grid storage applications . However, the mass application of LIBs, especially in the latter two applications, requires reductions in cost and environmental impact and improved sustainability. , The cathode materials used in LIBs contribute significantly to these factors. This is because the majority of Li-ion batteries utilize layered LiMO 2 oxide cathode materials, where M = Co (LCO), a mixture of Ni, Mn, and Co (NMC), or a mixture of Ni, Co, and Al (NCA).…”