Batteries.

Scientists from Japan Advanced Institute of Science and Technology (JAIST) have developed a new anode material that could overcome the slow charging times of conventional lithium-ion batteries.

The technology uses a carbon-based anode with ∼17 wt% of nitrogen doping (introduction of nitrogen impurities) with charging capability at 18.6 A g⁻¹.

The findings could pave the way to fast-charging and durable batteries for electric vehicles as the industry looks to cut the charge time of EVs from around 40-minutes to be below 15 minutes. 

The team of scientists from JAIST was led by professor Noriyoshi Matsumi, and included: professor Tatsuo Kaneko; senior lecturer Rajashekar Badam,; JAIST technical specialist Koichi Higashimine; JAIST research fellow Yueying Peng, and JAIST student Kottisa Sumala Patnaik.

The team’s findings were published online in the journal Chemical Communications.

Professor Matsumi said: "The extremely fast charging rate with the anode material we prepared could make it suitable for use in EVs. Much shorter charging times will hopefully attract consumers to choose EVs rather than gasoline-based vehicles, ultimately leading to cleaner environments in every major city across the world."

New battery material

The precursor material for the anode is poly (benzimidazole), a bio-based polymer that can be synthesized from raw materials of biological origin was calcinated at 800°C. 

Durability tests using half-and full-cells showed the proposed anode material retained around 90% of its initial capacity after 3,000 charge-discharge cycles at high rates.

The researchers verified the successful synthesis of the material and studied its composition and structural properties using a variety of techniques, including: scanning electron tunneling microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy.

A method being investigated to cut charge times is increasing the diffusion rate of lithium ions, which in turn can be done by increasing the interlayer distance in the carbon-based materials used in the battery's anode. 

While this has been achieved with some success by nitrogen doping there is no method easily available to control interlayer distance or to concentrate the doping element.

Modifications to the structure of the polymer precursor could lead to even better performance, which might be relevant for the batteries not only of EVs, but also of portable electronics. 

Vehicle OEM Honda Motor has announced plans for a battery sharing service for electric tricycle taxis in India using its swappable lithium-ion batteries.

Honda aims to eliminate user concerns around short range, long charging time and high costs through the use of swappable batteries scheme.

The scheme is due to begin in the first half of next year, and follows demonstration testing in India in February when 30 units of electric rickshaw taxis were driven for a total of more than 200,000 km.

Rickshaw drivers will be able to stop at a battery swapping station in the city and swap a low remaining charge battery for a fully-charged MPP e: battery.

The Indian-made Honda Mobile Power Pack e: has a rated voltage of 50.26V, a rated capacity of 26.1Ah/1.3kWh and weighs 10.3Kkg.

To begin this service, Honda will establish a subsidiary in India that will install a number of Honda Mobile Power Pack Exchanger e: as battery swapping stations and conduct battery sharing service in the city. 

Honda will work with electric rickshaw manufacturers and begin the service in selected cities first and then expand to other areas in stages. 

Minoru Kato, chief officer, life creation operations, Honda Motor, said: “The pack has huge potential to electrify all kinds of devices including small-sized mobility products and expand the use of renewable energy. 

“By offering a battery sharing service in India, Honda will contribute to the accelerated electrification of rickshaws and expanded use of renewable energy. 

“Moreover, Honda will continue serving people worldwide with the joy of expanding their life’s potential by further expanding the utilisation of the MPP into broader areas.”

Battery swapping services

Last year, government-owned fossil fuel firm IndianOil partnered with transport infrastructure power company Sun Mobility to set up electric vehicle battery-swapping stations at select fuel stations in cities across India.

A state-of-the-art battery swapping station has been inaugurated at Kapoor Service Station, one of Indian Oil's leading retail outlets in Chandigarh, in northern India.

In April, China fossil fuel company Sinopec signed a strategic agreement with NIO to fit one sixth of its filling stations with the car maker's battery swap facility by 2025.

This represents a big step up for China firm NIO Power, which plans to boost the number of its battery-swap stations from 201 to 5,000 over the next few years.

The new stations are not only fully automated but allow EV drivers to swap their depleted battery for a fully charged one in four-and-a-half minutes with a click of a single button 

In May, Honda was part of a consortium of motorcycle OEMs that joined forces to define the standardised technical specifications of swappable lithium-ion battery system for vehicles.

Other vehicle OEMs were KTM, Piaggio and Yamaha Motor.

The firms signed a letter of intent to create a Swappable Batteries Consortium for Motorcycles and Light Electric Vehicles belonging to the L-category: mopeds, motorcycles, tricycles and quadricycles.

Researchers at Chalmers University of Technology have pushed the performance of electrode material for sodium batteries so it matches lithium-ion batteries.

Using a novel graphene, the team at the Swedish institute reported the specific capacity for sodium ions was 332 milliampere-hours-per-gram— almost ten times that of the capacity of sodium intercalation in standard graphite.

The article “Real-time imaging of Na+ reversible intercalation in “Janus” graphene stacks for battery applications” was published in the journal Science Advances. 

Sodium ions are larger than lithium ions and interact differently, which means they cannot be efficiently stored in the graphite structure— unlike lithium-ion cells where the graphite anode allows better ion intercalation.

Chalmers’ research uses Janus graphene (named after the two-faced ancient Roman God Janus) due to its asymmetric chemical functionalisation on opposite faces of the graphene.

The upper face of each Janus graphene sheet has a molecule that acts as both spacer and active interaction site for the sodium ions. 

Each molecule, in between two stacked graphene sheets, is connected by a covalent bond to the lower graphene sheet and interacts through electrostatic interactions with the upper graphene sheet. 

The graphene layers also have uniform pore size, controllable functionalisation density, and few edges.

Jinhua Sun, from the Department of Industrial and Materials Science at Chalmers and first author of the scientific paper, said by adding the molecule spacer  when the layers were stacked together, the molecule creates a larger space between graphene sheets and provides an interaction point— which leads to a significantly higher capacity.

Vincenzo Palermo, affiliated professor at the Department of Industrial and Materials Science at Chalmers, said: “Our Janus material is still far from industrial applications, but the new results show that we can engineer the ultrathin graphene sheets— and the tiny space in between them— for high-capacity energy storage.”

Metals firm Sumitomo Metal Mining (SMM) is set to expand its production capacity of lithium-ion cathode materials for electric vehicle batteries. 

Plans include establishing a new plant in the Besshi area (Niihama City, Ehime Prefecture) and expanding production capacity at its Harima Refinery (Harima-cho, Kako-gun, Hyogo Prefecture), both in Japan.

The production capacity of cathode material is planned to be 2,000t/month.

The new plant for nickel-based cathode materials will be opposite SMM’s existing cathode material plant.

Overall capital expenditures for both sites will include: 40 billion yen for the new plant and seven billion yen for the Harima Refinery. 

Construction work is due to be completed in 2025. 

SMM said the production processes will consist of state-of-the-art equipment so the cathode materials can be produced from the start of operation. 

In its 2018 three-year business plan, SMM set a goal of reaching a production capacity of 10,000t/month of cathode material by the end of the 2024. 

This project is adopted by the country’s Ministry of Economy, Trade and Industry as a “Program for Promoting Investment in Japan to Strengthen Supply Chains.” 

SMM will use this grant appropriately in our business to promote the development of Japanese industries. 

Scientists at Oak Ridge National Laboratory (ORNL) have developed a solvent that enables a “more environmentally friendly” process for recycling lithium-ion batteries.

The ORNL-developed wet chemical process uses triethyl phosphate to dissolve the binder material that adheres cathodes to metal foil current collectors in lithium-ion batteries.

The method can recover cobalt-based cathodes, graphite and other valuable materials like copper foils for reuse in new batteries.

Oak Ridge National Laboratory researcher Yaocai Bai told BEST: "We are working with the battery industry and several companies are interested in this patented technology.

"The pyrometallurgical process involves the high energy cost of using high-temperature kilns and the detrimental generation of gaseous pollutants. The hydrometallurgical process involves caustic reagents and wastewater treatment. In contrast, our method utilises a green solvent that can be recycled and reused, making the process more environmentally friendly.

"The cost of this process is currently being evaluated. We are using the EverBatt model developed by the DOE ReCell Center to study both the cost and environmental aspects of our process. We believe the cost is low because of the reusability of the green solvent."

The use of, triethyl phosphate enabled the recovery of cobalt-containing cathodes, such as NMC622, by dissolving the polymeric binder of poly (vinylidene fluoride). 

Electrochemically active materials were separated from cathode scraps collected at the manufacturing step of electrodes through a solvent-based separation method without jeopardizing their physical characteristics, crystalline structure, and electrochemical performance. 

The team reported the recovered aluminum foils had no sign of corrosion and the polymeric binder could be recovered via a non-solvent-induced phase separation.

Additionally, recovery of cathode materials from spent cells was achieved using refined separation parameters based on the recycling of cathode scraps.

ORNL’s Ilias Belharouak said: “With this solvent, we’re able to create a process that reduces toxic exposure for workers and recovers valuable, undamaged, active NMC [nickel-manganese-cobalt] cathodes, clean metal foils and other materials that can be easily reused in new batteries.” 

To date, the tem has only tested the technology on a "few kilograms" of battery scrap.