Sunday, October 30, 2016

Three-layer electrode structure design to improve the energy density of lithium batteries 30%

Yang Yuan, an assistant professor at Columbia University's School of Materials Science and Engineering, has developed a new approach to increasing the energy density of lithium-ion batteries. His three-layer structure of electrodes in the bare air environment to maintain stability, thus making the battery more durable, further reduce the manufacturing cost. The study can increase the energy density of lithium batteries 10-30%, related papers published in early October in the "Nano Letters" periodicals.
Graphite / PMMA / Li three-layer electrode in a battery electrolyte for 24 hours before (left) and after (right). Prior to immersion in the electrolyte, the three-layer electrode is stable in air. After soaking, lithium and graphite reaction, the color turns yellow. Source: Columbia University
"When lithium batteries are charged for the first time, they lose as much as 5-20% of their energy in the first cycle," Yang said. "We have been able to avoid this loss through structural improvements. The approach has great potential for increasing battery life and is expected to be used in portable electronic devices and electric vehicles. " gmf32024abtw
During the first charge after production, a portion of the electrolyte in the lithium battery will change from a liquid state to a solid state due to a reduction reaction and adhere to the negative electrode of the battery. This process is irreversible and reduces the stored energy of the battery.
In the current electrode manufacturing technology, this process to bring the loss of about 10%, but for high-capacity next-generation anode material, such as silicon, the loss will reach 20-30%, which will greatly reduce the battery Of the actual available capacity.
In order to compensate for such initial loss, the conventional method is to add some lithium-rich material to the electrode. However, since most of these materials are unstable in the air environment, they must be manufactured in dry air, which is completely free from moisture, and therefore, the manufacturing cost of the battery is greatly increased.
Yang Yuan developed the three-electrode structure is to ensure that the electrode can be completed in the ordinary air environment to complete the manufacturing.
First of all, he used a layer of "PMMA" (that is, common plexiglass material), to isolate the lithium and air and moisture contact; PMMA polymer and then add a layer of artificial graphite or silicon nanoparticles and other active materials; He allows the PMMA polymer layer to dissolve in the cell electrolyte, thereby conducting lithium and the electrode material. msp430f436ipzr
"This allows us to avoid the air contact between unstable lithium and lithiated electrodes, which can be done in normal air environments and make it easier to produce battery electrodes," Yang explained.
Three-layer structure of the electrode production process: PMMA in the initial state to ensure that lithium does not react with the moisture in the air. When PMMA is dissolved by the battery electrolyte, the graphite contacts with the lithium to compensate for the initial loss due to the reduction of the electrolyte. Source: Columbia University
Yang's method reduced the loss of the existing graphite electrode from 8% to 0.3% and the loss of the silicon electrode from -13% to -15% (negative indicates that the capacity of the battery was taught as the initial state due to the addition of the new lithium material There is an increase). The excess lithium can compensate for the loss of capacity in the subsequent cycle, and thus the cycle life of the battery can be further enhanced.
Li-ion battery energy density (or capacity) in the past 25 years has maintained an annual growth rate of 5-7%, and Yang Yuan research to further improve the growth rate provides a feasibility program. His team is now working to reduce the thickness of PMMA coating in order to reduce its proportion in lithium batteries lower, and strive to achieve industrial production.
"The three-layer electrode design is cleverly designed to produce lithium metal-containing electrodes under normal air conditions," said Yale Wang, assistant professor of chemistry at Yale University. "The initial coulombic efficiency of the electrode has been a major challenge for the lithium-ion battery industry, This simple and effective compensation technology will cause great interest.

Monday, October 10, 2016

Intel OEM Spreadtrum 14nm chip sample this month

Intel has the world's most advanced semiconductor technology in the FinFET process than other manufacturers more than two years in advance of production, 14nm FinFET process although the dystocia, but still than TSMC, Samsung earlier, and Intel's process is the best , The gate distance is the real 14nm level, the other two are water. From the beginning of the transition began in the first half, Intel foundry as a breakthrough point, to win over LG Electronics, and now a customer confirmed that China's Spreadtrum will also use Intel 14nm process foundry, the fastest chip-related October You can sample.
Intel has no doubt in the wafer manufacturing strength, there have been sporadic OEM cooperation, but not many customers, mainly FPGA companies such as Altera, the results of Intel's own customers to the acquisition. Spreadtrum for Intel is not an outsider - Spreadtrum and another company Rui Dike were purple company acquired, and later set up a Unisplendour Company, and Intel Corporation to spend $ 1.5 billion stake in exhibition Rui, accounting for 20% of shares, That is, Intel is now a major shareholder of Spreadtrum. VKI50-12P1
Intel spent so much money to buy shares will naturally not be no good, in addition to planning the Chinese market, it is estimated that OEM cooperation is one of the contents of the negotiations before. Spreadtrum's CEO Li Liyou last year, said on 2016 will use Intel 14nm process foundry chip, there are media broke the news that Intel's 14nm process based on the chip can be the fastest in October to sample, progress is still very fast.
The news pointed out that Spreadtrum's 14nm chip will attract Samsung's orders, is expected to related Samsung mid-range phone will come out in 2017. Samsung has long been the company's VIP customers, although we rarely see based on the Spreadtrum chip (but also a lot of Spreadtrum baseband) smart phone, but in the 3G chip and overseas markets, Samsung Indeed there are many mobile phone is the use of Spreadtrum chip.
According to statistics in June of this year, Spreadtrum + Reddy in the global mobile phone chip market share reached 25.4%, more than MediaTek 24.7%.
On the other hand, cooperation with Intel does not mean that Spreadtrum to give up TSMC, they will still use the latter's 16nm and 28nm process, which is the first use of TSMC SC9860 16nm FFC process mobile phone chips, competitors MediaTek P20, The end of this year will be able to market.
Spreadtrum's accession to the Intel OEM business is a good start, after Intel announced the expansion of foundry business, we know that a customer is LG Electronics, in the 14nm and the future 10nm process OEM, LG will be Intel OEM business, an important partner, but LG ARM chip from the research for a long time, has not broken any movement, far worse than the Samsung Exynos processor. PM15CSJ060
According to the original text, Intel now has about 2,000 employees in China, South Korea, Japan and other Asian customers in Shanghai, there is a team dedicated to serving Chinese customers.