A recent study, led by Professor JaePhil Cho in the School of Energy and Chemical Engineering at UNIST has unveiled a new anode material, designed to help speed up fast charging in new electric cars with longer range. The key is to make many channels through which graphite can pass lithium ions quickly, and thinly coat silicon with nano-thickness on it. Applying this technology to future electric vehicle batteries will contribute to shortening charging time and increasing mileage.
It has become important to increase the capacity of the secondary battery, which is a power source, while reducing the charging time while paying attention to electric vehicles. However, existing graphite cathode materials have a small capacity to store lithium ions, and when charged at high speed, lithium metal precipitates on the surface of the cathode material, deteriorating battery performance and safety.
As a material to overcome the disadvantages of graphite anode materials, silicon materials, which are 10 times larger than graphite, are attracting attention as next generation anode materials. Silicon materials, however, have a low electrical conductivity and a rapid change in volume during charging and discharging. For this reason, the technology to make lithium ion batteries that simultaneously realize high capacity and fast charging has been a difficult problem until now.
In this study, Professor Cho and his research team proposed a method to synthesize a graphite / silicon composite with a new structure to overcome the limitations of existing cathode materials. The ‘edge activated graphite / silicon composite’ synthesized by this method was charged 1.5 times faster under commercialized electrode conditions and the capacity increased by 50%.
“At the core of this technology is a ‘nickel catalyst reduction method’ that creates highways where lithium ions can be rapidly loaded into graphite and a ‘silicon nano coating’ that increases the capacity stably,” says Namhyung Kim in the Combined M.S./Ph.D. of Energy and Chemical Engineering, the first author of the study. “The new materials have problems with existing graphite and silicon “We have demonstrated the possibility of applying it to next-generation high-capacity cathode materials.”
Nickel can act as a catalyst to react carbon and hydrogen. Using this point, the researchers attached nickel to the edges of the graphite cathode material and reacted with hydrogen. As a result, the carbon at the edges of the graphite has turned into methane (CH 4 ) gas. When these reactions occur consecutively, a hole is formed in the edge of the graphite, and a path through which lithium ions can easily enter is opened. As the number of such passageways increases, the battery can be charged quickly as a result.
The researchers also fabricated a structure that thinly coated silicon with perforated graphite to increase capacity over existing graphite cathode materials. It is a combination of high conductivity of graphite and high capacity of silicon.
“Silicon nanoclay technology is used to coat high-performance graphite / silicon composites evenly on the surface of graphite with silicon (about 20 nm or less) of the hair,” says Professor Cho. “The whole process is relatively simple and cheap, so it is possible to mass-produce it.”
He adds, “This research can be successfully applied to cathode materials used in high-energy, high-power batteries, such as electric vehicles and high-energy storage (ESS).”
The Latest on: Battery charging
- Bengals RB Mark Walton is facing a drug charge in Florida on February 18, 2019 at 5:17 pm
MIAMI (AP) — Prosecutors say Cincinnati Bengals running back Mark Walton is facing a marijuana possession charge in Florida. Walton was arrested late Friday on an unrelated battery charge after police ... […]
- Oil Majors Double Down On Battery Investment on February 18, 2019 at 4:54 pm
Last year, the company announced the acquisition of a US$20-million stake in StoreDot, a developer of ultrafast charging battery technology. “Ultra-fast charging is at the heart of BP’s ... […]
- Was a Mars Rover’s Final Message to NASA ‘My Battery Is Low and It’s Getting Dark?’ on February 18, 2019 at 4:27 pm
At one point, Margolis said the rover’s final transmission “basically” translated as “my battery is low and it’s getting dark ... and then when the storm cleared, the rover would charge back up,” he s... […]
- Stabbing leads to attempted murder charge in Natchitoches Parish on February 18, 2019 at 3:29 pm
A Many man faces an attempted murder charge after Natchitoches Parish deputies say he stabbed ... He's charged with attempted second-degree murder, home invasion and battery on a dating partner. The s... […]
- Port Richey man faces sexual battery charge after attacking woman at his home, deputies say on February 18, 2019 at 10:08 am
PORT RICHEY — A Port Richey man faces charges of sexual battery and domestic battery after an attack on a woman at his house that lasted an estimated 5 1/2 hours, the Pasco County Sheriff’s Office sai... […]
- Next Generation iPhone to Feature Frosted Glass Casing, Larger Battery, Wireless Accessory Charging, More [Report] on February 17, 2019 at 11:37 pm
Apple's next generation iPhones will feature a frosted glass casing, Ultra-Wide Band (UWB) for indoor positioning, the ability to wirelessly charge accessories, and more, according to analyst Ming-Chi ... […]
- Review: Mophie's Wireless Battery Case Adds USB-C Charging To iPhone XS, XS Max And XR on February 17, 2019 at 12:04 pm
Apple's latest generation of smartphones will get USB type-C support earlier than we thought. Starting next month, with the release of Mophie's Juice Pack Access, you will be able to charge any member ... […]
- Bengals RB Mark Walton arrested on battery charge in Miami on February 16, 2019 at 4:02 pm
MIAMI — Cincinnati Bengals running back Mark Walton is facing a battery charge after police say he got into an argument with a couple in Miami. The Miami Herald reports the 21-year-old football player ... […]
- Bengals running back Mark Walton arrested in Miami on battery charge on February 16, 2019 at 8:31 am
Cincinnati Bengals running back Mark Walton was arrested sometime late Friday night or early Saturday morning and has been charged with one count of misdemeanor battery. Walton, according to multiple ... […]
- Bengals RB Mark Walton arrested on battery charge on February 16, 2019 at 7:26 am
Bengals running back Mark Walton will have some legal trouble to sort out this offseason. According to multiple reports, Walton was arrested in Miami. Reports differ on whether he was arrested ... […]
via Google News and Bing News