It wasn't until Gu Wei raised a piece of yellow and shiny stone in his hand that Lin Han suddenly realized. It was the last time he returned from the bottom of the sea, he had picked up a piece of bright stone near the wreck. At that time, Xiao Gu Wei pestered him to ask for "Xiangxiang", and accidentally tore the mouth of the satchel, and the bright stone fell to the ground, and she "confiscated" it. Lin Han was drunk and cherished that his little life was finally saved, and he didn't take it seriously anymore when he thought of the stone chips under the sea all over the mountains. These days are busy, and I forget about it.

Gu Wei smiled and said, "Brother Lin, you recognize this stone piece, right?" Lin Han nodded and said, "Of course, I originally put it in my bag, but you took it away." ”

Gu Yunxuan said: "Lin Han, I'll say it for Gu Wei." Let's not ask you where you got this stone flake, just talk about the results of all kinds of experiments that Xiaowei has done around it these days, and tell you about it. ”

Lin Han took the bright stone tablet in Gu Wei's hand and looked at it repeatedly, and asked, "What kind of experiments do little junior sisters do?" ”

Gu Yunxuan said: "This is a priceless treasure! ”

Lin Han was taken aback, looked up at him, and asked, "What?" Invaluable...... The treasure? ”

Gu Yunxuan's face was rarely solemn, and he said word by word: "It is indeed a priceless treasure, I will tell you in detail." He turned around and sat on the chair, pointed to the bright stone tablet in Lin Han's hand and said, "I remember the first time you came to me, when Xiaowei was studying the charge and discharge experiment of sodium ions. She learned in a new scientific journal that scientists in Japan and New Zealand are working on the possibility of sodium ions as a new electronic energy source. ”

Lin Han said: "I have read this news, and now there are more and more teams and institutions developing sodium ions as new energy, but it still seems that it cannot be popularized, and there still seems to be a bottleneck that cannot be bypassed." ”

Gu Yunxuan nodded and said, "It's basically such a situation." Although Xiaowei is not meticulous, she has also come up with the bottleneck you mentioned. Sodium-ion batteries can be produced, but why can't they be widely used? Not because the raw material is expensive, sodium, the sixth known conventional element, can be found everywhere in the world, both on land and in the sea, and the cost is extremely cheap and very easy to extract. What is really expensive is that the developed sodium-ion battery, its electrode material electronic conductivity and sodium ion migration rate cannot be increased to even the lowest value we need. This means that the battery cannot be charged and discharged at large current, and it may take 24 hours or more to charge once; And with it, once there is a high-power consumption device that needs an instantaneous dense high current, it will be dumb and directly strike and rest. ”

Gu Yunxuan went on to explain: "To solve the problem that sodium-ion batteries cannot be charged and discharged with large currents, it is almost necessary to cross several fields, and to use other more neutralizing materials to complement them, and the simple problem is once again infinitely magnified to complexity, and the gains outweigh the losses." This is just one of the obstacles encountered in the development process of sodium-ion batteries, and there is no need to repeat the others. Now I'm going to tell you, this piece of bright stone you got back has all the excellent properties that can be used as a new type of electronic energy source, Xiaowei has done all kinds of experiments countless times, at first I didn't believe it, until I personally observed all her drills, I have to admit that this kid has found a miracle! ”

Lin Han was dumbfounded when he heard this, and looked at the bright stone piece in his hand fixedly, and doubted: "It's so magical?" ”

Gu Yunxuan said: "I'll save time, just use data to talk to you." The most optimistic theoretical assessment given by scientists of sodium-ion batteries, both at the beginning of development and so far, is that they can store seven times more power than existing lithium-ion batteries in the same volume. This is already a remarkable data, and it is still a review data that has temporarily overcome its various shortcomings at a high price; But do you know how much energy it will have if you use this bright stone flake as a raw material? ”

Lin Han rarely saw his teacher use this kind of surprising question to explain a topic, and asked in surprise, "How big will it be?" ”

Gu Yunxuan was silent for a moment, and said in a deep voice: "Under the same volume, the amount of electricity it can store is 100,000 times that of the existing lithium-ion batteries!" ”

"Yikes!" Lin Han exhaled subconsciously, his hand trembled, and he almost dropped the bright stone piece to the ground, wondering if he had heard it wrong. Then he almost jumped up: "What? 100,000 times? ”

Gu Yunxuan nodded calmly and repeated, "Yes, 100,000 times!" ”

"It can't be!" Lin Han instantly denied the answer: "There is no such raw material in the world!" How is this possible? Teacher...... Did Xiaowei get the data wrong? This piece of bright stone is just a ...... I picked up in the sea."

Gu Yunxuan interrupted him and said, "I also participated in Xiaowei's experiment. ”

Lin Han opened his mouth and froze in place. Gu Yunxuan didn't mean anything else, he was just explaining to Lin Han that I was involved in this experiment, do you still have to doubt the correctness of the conclusion?

Lin Han understands that his teacher's external name is an authority in biology, but this does not mean that his chemistry and physics are a mess. On the contrary, even Gu Wei has to do some physical and chemical experiments under the guidance of his uncle from time to time, so his skills can be seen from this. It is said that Gu Yunxuan's physical and chemical ability is weak, or it is not out of line, but it also depends on who he is compared with and what height he stands at. How could a pediatric experiment equivalent to sodium ion charging and discharging be difficult to stop him?

"The most amazing thing is," Gu Yunxuan continued: "Xiao Wei cut a very small piece of bright stone chips, entered the substantive test, and without any other elements mixed and matched, directly installed the exposed stone chips on the positive and negative electrodes, and it could almost be used as a battery!" We went around in a big circle, and finally we realized that this thing itself is a very powerful battery! ”

Lin Han's eyes were wide open, and he hadn't fully understood the teacher's words. Gu Wei spread out her palm to show him, the little girl's white palm was placed on the corner of a bright stone with the size of a fingernail, but the two sides had been inlaid with rough copper conductors.

Gu Yunxuan said: "I don't have time to repeat the test steps for you in detail, this positive and negative copper flakes are all wrapped in the most common lithium cobalt oxide and graphite, you can see how much energy such a small piece of stone flakes will have." ”

Gu Wei turned around and quickly inserted the wire, connected the positive and negative poles on the stone chips, and finally connected it to a four-position socket, clapped her hands and grinned: "Brother Lin, the battery is done, what do you want it to do now?" ”

Lin Han looked at the small piece of bright stone intently, stretched out his hand and hesitated, "This ...... Can it be used? It's as simple as that? ”

Gu Wei pulled an energy-saving light bulb with a wire latch attached to it and inserted it into the socket. Almost at the same time, the light bulb lit up silently, and the white blazing light was dazzling. Lin Han was extremely surprised and froze in place.

Gu Wei was very proud and said, "It's nothing, give me your phone." Lin Han's face was full of doubts, and he took out the phone and handed it to her. Gu Wei found the charging cable, connected the phone at one end, and installed the socket at the other. The miracle happened again, Lin Han's phone screen lit up, and the charging sign kept flashing to indicate that the unit was charging!

Lin Han almost raised his eyebrows when he saw it, and said, "This ...... It's not scientific! Without an inverter, how can it send out alternating current?! Gu Yunxuan laughed and said, "That's a good question, guess what." ”

Looking at the teacher's mysterious smile and smug look, Lin Han's doubts gradually turned into anticipation, and finally he became a little excited, grabbed Gu Wei's hand, and said in a trembling voice: "Little junior sister, tell me quickly, this is ...... Here's why! Isn't it, isn't it ......?"

Gu Wei looked innocent and pouted: "It's not a big fuss, it's actually easy to explain." The bright stone chip is not a battery at all, because of the special molecular structure inside, it can be used as a power supply at home! ”

Lin Han was still at a loss, and looked up at Gu Yunxuan anxiously, with a look of anticipation and curiosity. Gu Yunxuan smiled and nodded: "Xiao Wei is not wrong, this is her most thorough and comprehensive summary of the bright stone tablets, no matter how weak your physical and chemical knowledge is, can't you still understand what she means?" ”

Lin Han thought thoughtfully, quickly used his brain, and asked tentatively, "Could it be ...... The molecular structure inside the bright stone flakes is special, and the direction and size of the current can be changed at will and at any time. ”

Gu Yunxuan smiled and said, "The son can be taught!" It's just junior high school knowledge, have you eaten all the food for so many years? ”

Lin Han didn't understand the ridicule of his teacher, pointed to the small piece of bright stone and stammered: "But...... But...... This stone flake actually has such characteristics! What is ......" He was so stunned that he couldn't even answer, and sat down on the chair next to him.

Gu Yunxuan said: "Look at your expression, I don't know the magic of this stone...... This is strange, let me ask you again, where did you get this stone in the sea? What is the surrounding environment? ”

Lin Han was startled, and immediately recalled the 10,000-meter ocean trench, the bottomless abyss of the black hole, the nest of the giant octopus, and the god-like existence of St. Mary...... blurted out, "That big hole! ”

Gu Yunxuan, Gu Wei's uncle and nephew tightened their brows, and asked in unison, "What big hole?" Lin Han looked up at the two of them fiercely, his mouth open but he didn't make a sound, hesitating whether to tell them the truth.

Gu Yunxuan didn't doubt him, and said slowly: "No matter where you got this stone piece, it is really a treasure!" There is no doubt about this, Xiaowei and I have done almost all the experiments possible, and we have also thoroughly analyzed and observed the detailed molecular structure inside, it is amazing! As he spoke, he picked up a notebook on the table and handed it to Lin Han, and continued: "There are many experimental processes and analysis conclusions recorded here, as well as the opinions I have attached, you can take it back and take a closer look...... How to make use of this bright stone tablet, it seems that there really is a big article that can be done. ”

Gu Yunxuan got up, threw down Lin Han, who was stunned, and left slowly. Gu Wei carefully took off the phone and handed it back to him, and said, "Brother Lin, I still have a lot of experiments to show you, this stone can be dissolved with sodium ions very smoothly, and the changes after that ...... It's more complicated, I thought you must know it well......"

Lin Han took the phone, looked at the notes oblivionly, and suddenly stood up and said, "Oops, the teacher hasn't eaten lunch yet...... Quick, go up with me! Grabbing Gu Wei's little hand, he hurriedly ran to the door.

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(Tianjin)