The next generation of lithium-ion batteries will be more efficient with higher energy density and better over-time performance, according to a report from the UK-based Faraday Institution. It focuses on development of new and existing cathode materials, and their pros and cons.
The perfect cathode should offer high energy density, good thermal stability, and a long cycle life – all at a low cost. Of the known materials, none is the perfect solution it said. Lithium cobalt oxide (LMO) has for three decades been considered the original lithium-ion battery cathodes, but new chemistry such as the NMC oxide layer cathodes, containing nickel, manganese and cobalt is a challenger, and has far better energy density, it said.
It is particularly interesting for electric vehicles (EVs) and portable applications. LMO is a spinel-type material operating at much higher voltages, 4.0 V, and has faster energy release than other cathodes. The cost level is moderate thanks to cheap manganese, but the low capacity limits the use of LMO cathodes. The LMNO variety containing nickel reduces this disadvantage. LMO cathodes could be a cheaper option to other cathodes in the future, the report noted.
The Faraday Institution has identified two different scenarios for the development of cheaper cathodes with a better performance. In scenario 1, NMC and the cheaper lithium-iron-phosphate (LFP) will dominate the market, with a gradual transition towards LFP chemistry in the 2040s.
New products like the Qlin NMC pack from Chinese battery maker CATL offer up to 250 Wh/kg, significantly higher than for LFP batteries. In scenario 2, next-generation batteries (sodium, Li-S) will rapidly take over 50% of the European EV battery market, it said.
New innovations in NMC cathode synthesis will improve discharge properties and increase thermal stability, a weak point for the aluminum-based versions. High nickel content in NMC is being announced by EV manufacturers Tesla, Renault and VW.
The cobalt-free LFP chemistry has attracted Chinese manufacturers. The cell level energy density has increased from 90 Wh/kg in 2010 to 160 Wh/kg in 2022, and still rising thanks to a novel cell-to-pack technology.
The Faraday Institution also lists a number of promising technologies, such lithium-sulfur, sodium-ion (low-cost alternative) and multivalent chemistries. The Chinese manufacturer HiNa Battery Technology is expected to launch an EV sodium-ion battery pack in late 2023. Lithium-sulfur cells could achieve ultra-high energy densities, up to 2,600 Wh/kg, but few cells will ever reach more than 500 Wh/kg.
Image: Faraday Institution
