$QuantumScape(QS)$ 请教一下各位朋友公告中的“We are pleased to report new data on our zero external pressure efforts: 70x85 mm single-layer cells have reached 800 cycles with energy retention above 80%, under our gold-standard test conditions – 100% depth of discharge, 25 °C and 1C average charge/discharge rates” 中，"zero external pressure 与之前的“no externally applied pressure"作何解？另外提到的实验环境中的 "1c average charge/discharge rates"中的1c 是什么意思 ？