在偏远环境中如何收集、储存电力？

谢钰洪

Today wirelessly connected devices are performing an expanding array of applications. Yet how do you power these devices in situations where and when reliable electrical sources are not practically available？ Research from the University of Utahs College of Engineering points to a possible solution in the form of a novel type of battery called a pyroelectrochemical cell （PEC）.

The device is charged by changing temperatures in the surrounding environment， whether its inside a car or aircraft or just under the soil in an agricultural environment. In theory， the PEC could power sensors for IoT  （Internet of Things） applications that would otherwise be impractical to recharge.

The PEC uses a pyroelectric composite material， as the separator in an electrochemical cell. The material consists of porous polyvinylidene fluoride （PVDF） and barium titanate nanoparticles. This materials electrical properties change as its heated or cooled， which decreases or increases the polarization of the pyroelectric separator. Changing temperatures create an electric field inside the cell， pushing ions around and enabling the cell to store energy.

“It stores electricity in whats called an electric double layer， which stores the charge in positive and negative layers of ions.” said lead author Tim Kowalchik， a researcher in Warrens lab. “When you heat and cool the system and youre storing electrochemical energy， youre changing the amount of positive or negative ions that are in those layers.” The cell could produce up to 100 microjoules（焦耳） per square centimeter from a single heating/cooling cycle， which is not much energy， but enough to be useful for IoT purposes， according to the research.

“You want to monitor the condition of your car， the condition of machines， the condition of plants and soil and those kinds of things. Those types of sensors are generally going to be quite a bit lower power than your smartwatch or your phone， which have a display and theyre transmitting a lot of data，” said Roundy， another researcher. “The sensors were talking about might just give periodic updates and they operate autonomously. They dont have an interface or a screen.”

（材料來自Science网站，有删改）

1. Whats worrying us when it comes to wireless devices？

A. Shockingly wide applications.

B. Unsustainable power support.

C. Poor practical adaptability.

D. Quick power consumption.

2. Whats the main idea of Paragraph 3？

A. The working principle of the PEC.

B. The composition of the PEC.

C. The performance of the new material.

D. The complex design of the device.

3. Whats the function of the electric double layer？

A. To stimulate ions.

B. To produce energy.

C. To preserve electricity.

D. To adjust the system.

4. What can be inferred from what Roundy said？

A. All your devices should be closely watched.

B. Smart watchers sensors are better data senders.

C. The new device is only workable to some sensors.

D. The new devices sensors can transmit big data.

1. B。解析：推理判断题。材料第一段提到“然而，在实际无法获得可靠电源的情况下，您如何为这些设备供电？”由此推断出目前对于无线设备我们比较担心的一个问题是持续的可靠电力，以此引出材料的话题。B选项“不可持续的电力支持”与材料相符，故选B。

2. A。解析：主旨大意题。材料第三段有四句话，第一句和第二句谈及的是所用的材料PEC及其特性，第三句和第四句介绍该材料如何收集和储存电力，由此A选项“PEC材料的工作原理”与材料内容相符，故选A。

3. C。解析：细节理解题。材料第四段的第一句提到“它将电储存在所谓的双电层中，将电荷储存在正负离子层中”，由此可知双电层的作用主要是储存电力。C选项“储存电力”与材料内容相符，故选C。

4. C。解析：推理判断题。根据材料最后一段Roundy所說的话“你想监测你的汽车状况、机器状况、植物和土壤状况及诸如此类的东西。这些类型的传感器通常比有显示屏的、可以传输大量数据的智能手表或手机功耗低得多。我们所说的传感器可能只是定期更新，它们会自主运行。他们没有界面或屏幕”，以及第二段第二句话“理论上，PEC可以为物联网应用程序的传感器供电”可知，研究的新型电池可以用来支撑这类传感器。C选项“这种新设备只适用于某些传感器”与材料相符，故选C。