Batteries.

Sumitomo Metal Mining has recovered a high-purity nickel-cobalt mixture from used lithium-ion batteries.

The Japan firm has verified that nickel and cobalt recovered from secondary batteries can be reused as a raw material for lithium-ion cathodes. 

The materials produced at its pilot plant in Niihama City, Ehime Prefecture, performed as well as batteries using existing raw materials derived from natural resources, the company said. 

Additionally, Sumitomo was able to produce a soluble slag that enables lithium recovery by pyrometallurgical smelting processes. 

The company first developed a recycling process to recover cobalt at the pilot plant using a combination of pyrometallurgical smelting and hydrometallurgical refining processes in 2019.

Sumitomo is now able to recycle copper, nickel, cobalt and lithium from used batteries. 

In 2017, the existing smelting and refining processes at the Toyo Smelter & Refinery (Saijo City, Ehime Prefecture) and the Niihama Nickel Refinery (Niihama City, Ehime Prefecture) were used in the implementation of copper and nickel recycling.

A Sumitomo statement read: “The demand for the nickel and cobalt used in EVs is going to expand. 

“However, stable supply is a major issue, and there are unbalances in the regions producing these resources and the location of extraction technologies. Demand for recycling of these resources is growing greater than ever. 

“If we are able to commercialise this process, which has verified ‘battery to battery’ recycling, we expect to be able to take the domestic sustainable circular economy to the next level and to make contributions to resource recycling in response to global resource depletion.” 

Chemicals firm BASF is set to build a prototype battery recycling plant in Germany to develop a method of recovering key lithium-ion materials from end-of-life batteries.

The plant will be located at the site of its cathode active materials (CAM) plant in Schwarzheide, with commissioning planned for early 2023.

The prototype recycling plant will allow for the development of operational procedures and optimisation of technology to recover lithium, nickel, cobalt and manganese as well as off-spec material from cell producers and battery material producers. 

The extracted metals will be used to produce new cathode active materials.

Dr. Matthias Dohrn, senior vice president, precious and base metal services at BASF, said: “With this investment in battery recycling, plus leading process technology for manufacturing of cathode active materials, we aim to ‘close the loop’ while reducing the CO₂ footprint of our cathode active materials by up to 60% in total compared to industry standards.”

BASF’s investment supports the European Commission’s agenda towards a European battery production value chain and is part of the ‘Important Project of Common European Interest (IPCEI)’ approved by the European Commission in 2019, under the European Union State aid rules. 

The plant’s location was announced in February.

Aggressive cathode expansion

In June, BASF is set to form a joint venture with Hunan Shanshan Energy to produce lithium-ion battery cathode active materials (CAM) and precursors (PCAM) in China.

German firm BASF will have a 51% share of the JV when it closes later this summer following the approval of the relevant authorities.

In May, materials firm Umicore and BASF entered into a non-exclusive patent cross-license agreement covering a range of lithium-ion cathode materials and their precursors.

A US team from the Washington University in St. Louis has developed a stable sodium-ion coin cell that could one day replace lithium-ion batteries.

The ‘cheaper and smaller’ technology uses a thin layer of copper foil on the anode side of the battery as the current collector.

Taking into account only the active materials, the energy density of the tested coin cells were in the range of 310-340 Wh/kg.

For the 100 cycles, the team tested at 2C-rate and 3C-rate with the cells showing a >99.9% capacity retention rate per cycle, which projects the cells can run for more than 200 cycles before reaching 80% of the initial capacity.

The technology is ready for commercial tests and optimisation, say the team.

In the anode-free battery the ions are transformed into a metal where they plate themselves onto the copper foil, before dissolving when returning to the cathode.

The research was published 3 May in the journal Advanced Science.

Previously, anode-free batteries were unstable, and grew dendrites that were attributed to the reactivity of the alkali metals involved, namely sodium.   

The technology was made in the laboratory of Peng Bai, assistant professor in the university’s Department of Energy, Environmental & Chemical Engineering in the McKelvey School of Engineering.

Bai told BEST: “Our focus here was the anode, which by itself (in a control cell) can run for more than 7,000 hours without degradation. 

“But we need a better cathode to make the anode-free full cell to achieve longer cycle life. 

“Once the optimised cathode material, either from us or from another research group or company, is identified the technology will be ready for commercialisation. It doesn't require any special facilities other than what people currently use for lithium-ion batteries.”

He added: “Our demonstration shows that in terms of energy density it is comparable to lithium-ion batteries. So wherever people want to lower the cost of their lithium-ion batteries, they can use this anode-free sodium battery. They would not notice performance differences, but save a lot of money.” 

The cost-saving for manufacturing the anode-free sodium (Na) battery comes from three aspects: the anode material (no need for anode materials like graphite); anode processing (no need to fabricate the graphite anode laminate); and the cathode material (Na-based materials are cheaper than lithium-based materials for synthesizing the cathode).

The concept of replacing lithium with sodium and removing the anode isn’t new, but the problem has been developing an anode-free battery with a reasonable lifetime, said Bai.

Bingyuan Ma, the paper’s first author and a doctoral student in Bai’s laboratory, said: “In our discovery, there are no dendrites; the deposit is smooth, with a metal luster. 

“This kind of growth mode has never been observed for this kind of alkali metal.”

Watching the battery in action, the researchers saw shiny, smooth deposits of sodium, which eliminates morphological irregularities that can lead to the growth of dendrites.

Image: Bingyuan Ma holding a transparent capillary cell. Bai’s Lab at the McKelvey School of Engineering is the only one in the world with such diagnostic cells. (Courtesy: Bai Lab)

An international team of researchers has developed a proof of concept technique for precisely tracking the movement of lithium ions moving through a polymer electrolyte within batteries.

The researchers used X-rays to determine the velocity and concentration of ions within a battery, then compared those results to theoretical models to determine the ion transport number, a fraction of electric current carried by ions in an electrolyte.

UK-based recycling development firm Ever Resource has been awarded £237,425 ($315,500) grant funding to produce lead oxides for enhanced lead-acid technologies from old batteries.

The cash from Innovate UK's 'Sustainable Innovation Fund (round 1)' framework will allow Ever Resource to begin testing its nanostructured lead oxides in commercial lead-acid batteries.