US colleges and universities develop a temperature-controlled charging method to fully charge in 10 minutes
A research report pointed out that when a lithium-ion battery is quickly charged at an ambient temperature below 50 degrees Celsius, the battery activity will be greatly reduced. A study by Pennsylvania State University found that during the charging process, if the lithium ion battery is continuously heated at 140 degrees Celsius for 10 minutes and then quickly cooled, the battery can be fully charged more quickly. In addition, this charging method can be used to charge the battery 2500 times. Under normal circumstances, rapid heating and cooling the battery will cause the battery to short circuit, but the use of a thin nickel foil layer can absorb excess heat and evenly distribute the charge throughout the battery pack. Specifically, it uses a thin nickel foil with a temperature sensor, connects the sensor to the switch, and controls the switch to make current flow through the metal foil, thereby quickly heating the battery, and then relying on the vehicle's cooling system to quickly cool the battery. It is worth noting that there are certain risks in heating batteries. Therefore, the industry currently bans this measure, and the program will not be mass-produced in a short period of time. Researchers said that in the field of batteries, this extreme behavior of heating the battery to above 60 degrees Celsius is often prohibited. Some people think that doing so will cause damage to the battery and significantly reduce battery life. Compared with the traditional on-board charging system, the temperature-controlled charging method of Pennsylvania State University takes less time and is more practical. However, until the risks of battery short circuit are resolved, we cannot yet see the mass production of this new technology. A ring split at one point and bent into a helical shape. This causes the washer to exert a spring force between the fastener's head and the substrate, which maintains the washer hard against the substrate and the bolt thread hard against the nut or substrate thread, creating more friction and resistance to rotation. Applicable standards are ASME B18.21.1, DIN 127 B. Spring Washer,Spring Lock Washer,Spring Steel Washer,Stainless Steel Spring Washers Taizhou Risco Stainless Steel Products Co.,Ltd , https://www.riscofastener.com
Spring washers are a left hand helix and allow the thread to be tightened in a right hand direction only, i.e. a clockwise direction. When a left hand turning motion is applied, the raised edge bites into the underside of the bolt or nut and the part that it is bolted to, thus resisting turning. Therefore, spring washers are ineffective on left hand threads and hardened surfaces. Also, they are not to be used in conjunction with a Flat Washer under the spring washer, as this isolates the spring washer from biting into the component that will resist turning.
The use and effectiveness of spring lock washers has been debated, with some publications advising against their use on the grounds that, when tight, the washer is flat against the substrate and gives no more resistance to rotation than a normal washer at the same torque. However, a spring washer will continue to hold the bolt against the substrate and maintain friction when loosened slightly, whereas a plain washer will not.
The benefit of spring lock washers lies in the trapezoidal shape of the washer. When compressed to loads near the proof strength of the bolt, it will twist and flatten. This reduces the spring rate of the bolted joint which allows it to maintain more force under the same vibration levels. This prevents loosening.