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Thallium Doping Boosts Thermoelectrics

Bad for people, but good for energy conversion

3 min read

24 July 2008--Engineers in the United States and Japan have found a new technique to improve the efficiency of a thermoelectric energy converter. Instead of decreasing the thermal conductivity, which is normally how efficiency is improved, they increased the electrical conductivity by doping it with the toxin thallium.

”It is for sure a significant development,” says Zhifeng Ren, a physics professor at Boston College who studies thermoelectrics but was not involved in the research. Thermoelectric efficiency, or ZT, is proportional to electrical conductivity, temperature, and thermoelectric power--the voltage produced in a material per degree. ZT is inversely proportional to thermal conductivity. Ren says that until now, no one has been able to produce a significant increase in the thermoelectric power (also called the Seebeck coefficient), and all improvements to ZT are the result of decreasing the thermal conductivity.

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Chinese Joint Venture Will Begin Mass-Producing an Autonomous Electric Car

With the Robo-01, Baidu and Chinese carmaker Geely aim for a fully self-driving car

4 min read
A black car sits against a white backdrop decorated with Chinese writing. The car’s doors are open, like a butterfly’s wings. Two charging stations are on the car’s left; two men stand on the right.

The Robo-01 autonomous electric car shows off its butterfly doors at a reveal to the media in Beijing, in June 2022.

Tingshu Wang/Reuters/Alamy

In October, a startup called Jidu Automotive, backed by Chinese AI giant Baidu and Chinese carmaker Geely, officially released an autonomous electric car, the Robo-01 Lunar Edition. In 2023, the car will go on sale.

At roughly US $55,000, the Robo-01 Lunar Edition is a limited edition, cobranded with China’s Lunar Exploration Project. It has two lidars, a 5-millimeter-range radar, 12 ultrasonic sensors, and 12 high-definition cameras. It is the first vehicle to offer on-board, AI-assisted voice recognition, with voice response speeds within 700 milliseconds, thanks to the Qualcomm Snapdragon 8295 chip.

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