Connect with us

Scientists at Argonne National Laboratory have made progress toward a higher-capacity lithium-ion battery to meet rising consumer demand.

With the growing number of electric vehicles on the road and an increasing reliance on consumer electronics, demand has never been greater for development of lithium-ion batteries (LIBs) that can sustain a higher energy capacity, or amount of charge stored within the battery.

Redesigning lithium ion battery anodes for better performance

Argonne scientists observed reversible volume and phase change of micrometer-sized phosphorus particles during charge and discharge. (Image by Argonne National Laboratory / Guiliang Xu.)

One way to increase the overall energy capacity of LIBs is to increase the energy capacity of the anode, or the negative electrode. For the past several decades, state-of-the-art LIBs have been made with graphite anodes. Graphite’s energy capacity is stable, meaning the capacity does not fade, and the material does not crack even after more than 1000 full charge-discharge cycles. However, graphite has a low theoretical energy capacity, which cannot meet the increasing energy demands of today’s society.

Argonne has unique abilities available at the APS and CNM. With the storage ring light source, we can probe the phase transformation during lithiation and delithiation, which allows us to see the reaction reversibility.” — Gui-Liang Xu, Argonne chemist

In a new study, a team led by researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have demonstrated the increased capability of a potential new, higher-capacity anode material. This composite material had originally been developed for sodium-ion batteries, which are more infrequently commercially used than lithium-ion batteries. This new study sought to apply the material to lithium-ion batteries.

Recently, two materials have been at the forefront of research for next-generation battery anodes — silicon and phosphorus. Both silicon and phosphorus have a theoretical energy capacity at least 10 times greater than graphite, meaning they could surpass the energy capacity requirements for LIBs. According to senior materials scientist and Argonne Distinguished Fellow Khalil Amine, the lead researcher of the Argonne study, silicon has two major issues. The first issue involves the high-volume expansion when silicon is lithiated during charging, which would likely cause the anode material to break apart. Cracking would lead to a loss of energy capacity, he explained.

The second issue involves a term called initial coulombic efficiency (ICE). When a battery goes through a full charge-discharge cycle, the charge output of the battery theoretically should match the charge input. However, some energy in the charge output is lost to the lithium reacting with the anode material. To develop a practical LIB, the ratio of the charge output compared to the charge input on the first charge-discharge cycle should be above 90%. This ratio is the ICE. With silicon, the ICE is less than 80%, which Amine explained renders it infeasible for practical use.

In their research, Amine, Argonne chemist Gui-Liang Xu, and their colleagues explored two potential types of phosphorus: black and red phosphorus. ​Phosphorus has a very high energy capacity,” Xu said. ​When we explored the material, we found that our anode material has a very high ICE of more than 90%.”

An ICE of more than 90% demonstrates that very few side reactions occur between the anode material and the electrolyte, so not much lithium is lost during the initial charging and discharging.

The team created their own anode composite composed primarily of black phosphorus — a highly conductive form of phosphorus with a high theoretical capacity — and conductive carbon compounds.

To create the composite, the researchers ground the bulk phosphorus material and conductive carbon into micrometer-sized particles, which increases the density of the anode.

When measuring the life cycles, or the total number of times a battery can be charged and discharged, Amine and his colleagues turned to Argonne’s Advanced Photon Source (APS) and Center for Nanoscale Materials (CNM), both DOE Office of Science User Facilities. Employing in-situ storage ring light source X-ray diffraction at the APS and in-situ scanning electron microscopy at the CNM, the team observed the anode’s phase and volume transformation during repeated charging and discharging.

Argonne has unique abilities available at the APS and CNM,” Xu said. ​With the storage ring light source, we can probe the phase transformation during lithiation and delithiation, which allows us to see the reaction reversibility.”

After showing the stability of the black phosphorous composite, the team investigated a composite with red phosphorus instead of black phosphorus. Black phosphorus, though significantly more conductive than red phosphorus, is too expensive for practical use in the market. With the red phosphorus composite, which is an economically viable option, the battery showed a similar stability and high ICE, with a very high practical capacity.

The team is currently working on a composite material made mostly of red phosphorus, and the material shows promising results, Xu said. ​We’re trying to initiate collaboration with industry partners so we can scale up this material, so it can be commercialized in the future.”

The research paper on the study, ​A practical phosphorus-based anode material for high-energy lithium-ion batteries,” appeared online on April 262020, in Nano Energy. The research project was funded by the Battery Materials Research Program in DOE’s Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office.

Source: ANL




Source link

0
Continue Reading

Technology

Vi Weekend Data Rollover Offer Extended Till April 17: All the Details

vi vodafone idea logo image gadgets 360 1600074342843

Vi (Vodafone Idea) has extended its weekend data rollover offer till April 17 from its previous end date of January 17. The company started the data rollover system back in October last year for its prepaid customers and it allows them to carry forward their daily unused data to the weekend. The updated time frame can be spotted in the terms and conditions section on the official Vi website. The weekend data rollover offer is still available with the same plans as before.

Vi website has been updated to show that this promotional offer is applicable from October 19 2020 to April 17 2021. This gives users another three months to enjoy the benefits of weekend data rollover as the offer was initially supposed to end on January 17. The minimum recharge value to avail this offer is Rs. 249 and is valid for unlimited packs with daily data. It is valid for Rs. 249, Rs. 299, Rs. 399, Rs. 449, Rs. 595, Rs. 599, Rs. 699, Rs. 795, and Rs. 2,595 plans. Currently, all these plans are listed on the website with weekend rollover along with an additional offer such as double data, 5GB extra data, or one year subscription to Zee5.

Every plan offered by Vi comes with some amount of data limit, that may not always be completely used. This results in some data being wasted as it resets the next day. With the weekend rollover system, Vi customers will be able to make use of whatever data is unused throughout the week, over the weekend.

Customers should note that unused data between Monday 0000 hours to Friday 2400 hours will be accumulated and made available between Saturday 0000 hours and Sunday 2400 hours. Post that, any and all unused data will be forfeited. The terms and conditions also state that Vi reserves the right to discontinue, modify, or withdraw the roll over or other product features subject to Telecom Regulatory Authority of India (TRAI) regulations.


What will be the most exciting tech launch of 2021? We discussed this on Orbital, our weekly technology podcast, which you can subscribe to via Apple Podcasts, Google Podcasts, or RSS, download the episode, or just hit the play button below.

Source link

0
Continue Reading

Technology

For preschoolers and soldiers: 4 new Acer Chromebooks meet military and toy safety standards

acer travelmate spin b3 lifestyle 1

Two models have antimicrobial coating and a spill-resistant gutter system to keep up to 11 ounces of liquid away from internal components.

The Acer TravelMate Spin B3 meets both military durability standards as well as toy safety rules.

Image: Acer

Even after several product announcements at CES 2021, Acer has more laptop news with five new products designed for the classroom. These laptops meet durability standards designed for military use as well as safety guidelines from toy manufacturers.

Several of the products feature zero-touch enrollment which means that IT departments can drop ship the laptops and automatically enroll the devices into a school’s system as soon as a student connects to the internet.

Here are the highlights of these new products. 

SEE: Hardware inventory policy (TechRepublic Premium)

Travelmate Spin B3

This convertible laptop is built for the toughest environment with extra durability. It is certified to meet ASTM toy safety standards and military-grade durability standards. It has a keyboard with mechanically anchored keys and a moisture-resistant touchpad. The processor is an Intel Pentium Silver and the battery life is up to 12 hours. The laptop has an HD webcam and Wi-Fi 6. According to Acer, the laptop can withstand up to 132 pounds of downward force, for those times when technology is too hard to grasp. 

The device has a drainage system that can redirect up to 11 ounces of liquid away from the internal components out of a drain in the bottom of the chassis. Also, the touch display is covered with a layer of antimicrobial Corning Gorilla Glass that can reduce the growth of odor and stain-causing microorganisms, according to the company. To boost the cleanliness factor even more, there is an optional BPR and EPA-compliant antimicrobial agent in the keyboard coating, touchpad, and palm-rest surface. A Wacom AES pen and a 5MP HDR front-facing camera are other optional features.

The Acer TravelMate Spin B3 (TMB311R-32) will be available in North America in April starting at $329.99; in EMEA in Q2 starting at €409; and in China in February, starting at ¥2,499.

Chromebook Spin 512 and 511

acer-chromebook-spin-512-r853ta-photo-2.png

Image: Acer

These two new convertible Chromebooks are also for the school environment with designs that meet military and toy durability standards and the specially designed gutter system to reduce damage from accidental spills.

The Spin 512 and Spin 511 come with an 8MP MIPI world-facing camera and an HDR webcam. Both have antimicrobial Corning Gorilla Glass display, ideal for education settings in which students share devices. Both devices have 360-degree hinges and N4500 and N5100 Intel processors. The new Acer Chromebooks will be available with up to 64GB eMMC storage and up to 8GB RAM.

The Acer Chromebook Spin 512 has a 3:2 aspect ratio HD+ IPS display. It also has an antimicrobial agent in the coating on the keyboard touchpad and palm area that is proven to show a consistently high microbial reduction rate against a broad range of bacteria. The Acer Chromebook Spin 512 will be available in North America in April starting at $429.99.

The Acer Chromebook Spin 511 is smaller with an 11.6-inch HD IPS display. 

The Acer Chromebook Spin 512 (R853TA) will be available in North America in April starting at $429.99; and in EMEA in March 2021, starting at EUR 399. The Acer Chromebook Spin 511 will be available in North America in April starting at $399.99; and in EMEA in March 2021, starting at €369.

Chromebook 511 and Chromebook 311

acer-chromebook-311-left-facing2.jpg

Image: Acer

These two new clamshell 11.6-inch laptops also feature compact designs and military durability. Both laptops meet leading toy safety standards. The 511 has a Qualcomm Snapdragon 7c Compute Platform and 4G LTE connectivity. Battery life is up to 20 hours, according to the company. It will be available in North America in April starting at $399.99.

The Chromebook 311 has a Mediatek MT8183 processor and was designed around industrial durability and toy safety standards for younger students. A touch screen is optional. It provides up to 20 hours of battery life. It will be available in North America in January starting at $299.99.

Also see

Source link

0
Continue Reading

Technology

GeoSim: Photorealistic Image Simulation with Geometry-Aware Composition

WIRELESS kimi lee M3RVFbqKGu4 unsplash 705x470 1

Humans can synthesize unperceived events in their heads, for instance, to imagine how an empty street would look during rush hour. The similar capability of computers may be useful in film making or augmented reality.

A recent paper proposes GeoSim, a realistic image manipulation framework that inserts dynamic objects into existing videos.

GeoSim Photorealistic Image Simulation with Geometry Aware Composition

Image credit: Unsplash/Kimi Lee

This method uses the data captured by self-driving cars to build a 3D assets bank. Then 3D scene layout from LiDAR readings and 3D maps is used to add vehicles in plausible locations. The Intelligent Driver Model is used so that the new objects have realistic interactions with existing ones and respect the flow of traffic. Neural networks are employed to seamlessly insert an object by filling holes, adjusting color inconsistencies, and removing sharp boundaries. It is the first approach to fully consider physical realism and outperforms prior research by qualitative and quantitative measures.

Scalable sensor simulation is an important yet challenging open problem for safety-critical domains such as self-driving. Current work in image simulation either fail to be photorealistic or do not model the 3D environment and the dynamic objects within, losing high-level control and physical realism. In this paper, we present GeoSim, a geometry-aware image composition process that synthesizes novel urban driving scenes by augmenting existing images with dynamic objects extracted from other scenes and rendered at novel poses. Towards this goal, we first build a diverse bank of 3D objects with both realistic geometry and appearance from sensor data. During simulation, we perform a novel geometry-aware simulation-by-composition procedure which 1) proposes plausible and realistic object placements into a given scene, 2) renders novel views of dynamic objects from the asset bank, and 3) composes and blends the rendered image segments. The resulting synthetic images are photorealistic, traffic-aware, and geometrically consistent, allowing image simulation to scale to complex use cases. We demonstrate two such important applications: long-range realistic video simulation across multiple camera sensors, and synthetic data generation for data augmentation on downstream segmentation tasks.

Link: https://arxiv.org/abs/2101.06543




Source link

0
Continue Reading

Trending