【香港記事】陶大宇驚人演唱倒轉地球

一些線民對陶大宇的演唱倒轉地球的評語：成首歌既精髓就係個啲噓噓哈唏 美中不足係唱得太好了 好歌，好演員，娛樂觀眾無底線 人地笑我傻，我笑他人看不穿，真心尊敬佢做人態度。 呢首係最好嘅中文歌。 我都覺得陶大宇唱得很好！ 片段如下

倒轉地球（非柒頭版）Cover 廣州海珠橋 向陶大宇致

Rubber Electrolytes-based Batteries and Electric Vehicles

In most lithium-ion batteries, ions are moved by a liquid electrolyte. However, a slight damage of the battery may cause leakage of electrolyte, causing explosion or fire. Thus, people are looking into alternatives such as solid-state batteries, which can be made using inorganic ceramic material or organic polymers. Elastomers, or synthetic rubbers have superior mechanical properties. It has been found that this material when formulated into a 3D structure, acted as a superhighway for fast lithium-ion transport with superior mechanical toughness, resulting in longer charging batteries that can go farther. A team made of scientist from Korea Advanced Institute of Science and Technology and Georgia Institute of Technology is working on the rubber battery development. (1) 

 According to Reference 1, this rubber electrolyte is made during a simple polymerization process at low temperatures, this process generates robust and smooth interfaces on the surface of electrodes. These unique characteristics of the rubber electrolytes prevent lithium dendrite growth but allow a faster moving ions! 

 According to Reference 2, The rubber electrolyte-based lithium metal batteries allow high energy density exceeding 410 Watt-hours per kilogram (Wh/kgelectrode+electrolyte) and maintained a high energy density of 235 Wh/kgelectrode+electrolyte at a power density of 184 Wh/kgelectrode+electrolyte. Thus, electric vehicles equipped with the rubber electrolytes-based Li batteries can travel over 490 miles on a single charge, while that with conventional Li-ion batteries can do only 310 miles.

Scientists from Georgia Tech; Photo: Georgia Tech 

Reference:

Rubber material holds key to long-lasting, safer EV batteries (techxplore.com)

A Battery Breakthrough, Made from Rubber - Tech Briefs

 References (1) https://techxplore.com/news/2022-01-rubber-material-key-long-lasting-safer.html (2) https://www.techbriefs.com/component/content/article/tb/stories/blog/40658

Shortage of Semiconductors and Demand in Used Cars

Semiconductors are substances with properties somewhere between a conductor and an insulator; conductors conduct electricity and insulators do not conduct electricity. Integrated circuits (ICs), diodes, transistors and other electronic discrete components are made of semiconductors, whereas the materials of semiconductors are gallium arsenide,indium antimonide,germanium and mainly silicon. Silicon forms most of ICs. (1)

 

Metals, semiconductors and insulators are distinguished from each others by their band structures. Their band structures are shown in the figure below.

In metals, the conduction band and the valence band are very closer to each other. In semiconductors and insulators, the valance band and conduction band are separated by a forbidden energy gap（Eg）of sufficient width. In semiconductors at room temperature, the band gap is small, electrons jump the gap fairly easily, given the semiconductor limited conductivity. Semiconductor crystal used for ICs is high purity single crystal silicon, but impurities are often added to modify the electrical properties. Depending on the added impurities, there are n-type and p-type semiconductors. For details, please review Reference 1. 

 A semiconductor chip is an electric circuit with many transistors and wiring formed on a semiconductor wafer. An IC comprises numerous these components. A semiconductor is made by two steps: wafer processing and front-end process and back-end process. Wafer processing is further divided into deposition, photoresist coating, and etching. For details, please review Reference 1. These steps are tedious process, requiring precision and skills. Semiconductors are in short supply because of big demand for electronics and effects from former President Donald Trump’s trade war. (2) 

Later, because of COVID-19, supply chains are disturbed. This worsens the situation. In the year 2021, semiconductor chip shortage costs the global automotive industry maybe up to USD200 billion or more in revenue. These shortages have slowed down several original equipment manufacturers (OEMs) in production; thus, further extending the waiting period of certain vehicle models. As a result (one of the results), used car sellers across markets, including India, are enjoying a boom in demand. (3) 

 Reference: (1) https://www.hitachi-hightech.com/global/products/device/semiconductor/about.html. (2) https://www.cnbc.com/2021/02/10/whats-causing-the-chip-shortage-affecting-ps5-cars-and-more.html#:~:text=Semiconductors%20are%20in%20short%20supply%20because%20of%20big,coming%20months%20as%20demand%20remains%20higher%20than%20ever. (3) https://home.kpmg/in/en/blogs/home/posts/2022/01/semiconductor-chip-shortage-manufacturers-suppliers-mantra.html