Good news!
"Korean researchers have found a way to grow crystals that they say could end up in lithium-ion batteries capable of powering an electric vehicle for 1 million kilometres. ..."
"A research team ... has recently demonstrated a single-crystal synthesis technology that significantly extends the lifespan of cathode materials for electric vehicles. ...
Traditional nickel-based materials have a polycrystalline morphology composed of many tiny crystals which can undergo structural degradation during charging and discharging, significantly reducing their lifespan. ...
The researchers discovered that conventional polycrystalline materials synthesized below a certain critical temperature are prone to degradation with prolonged use in secondary batteries. However, when synthesized above this critical temperature, high-quality single crystals can be easily produced, leading to materials with superior longevity. This is due to a process called “densification“ which occurs above a certain critical temperature. During this process, the internal grain size of the material increases and the empty spaces within the material are densely filled. Densified single crystals are extremely hard and resistant to degradation over extended periods, significantly enhancing their durability. ..."
Traditional nickel-based materials have a polycrystalline morphology composed of many tiny crystals which can undergo structural degradation during charging and discharging, significantly reducing their lifespan. ...
The researchers discovered that conventional polycrystalline materials synthesized below a certain critical temperature are prone to degradation with prolonged use in secondary batteries. However, when synthesized above this critical temperature, high-quality single crystals can be easily produced, leading to materials with superior longevity. This is due to a process called “densification“ which occurs above a certain critical temperature. During this process, the internal grain size of the material increases and the empty spaces within the material are densely filled. Densified single crystals are extremely hard and resistant to degradation over extended periods, significantly enhancing their durability. ..."
From the abstract:
"High-Ni layered oxide cathodes are promising candidates for lithium-ion batteries due to their high energy density. However, their cycle stability is compromised by the poor mechanical durability of the particle microstructure. In this study, we investigate the impact of the calcination temperature on microstructural changes, including primary particle growth and pore evolution, using LiNi0.88Mn0.08Co0.04O2 (N884), with an emphasis on the critical calcination temperature for polycrystalline and single-crystal designs in high-Ni cathodes. As the calcination temperature increases, the primary particles undergo a rectangular growth pattern while the pore population decreases. Beyond a certain critical temperature (in this case, 850 °C), a sudden increase in primary particle size and a simultaneous rapid reduction in the pore population are observed. This sudden microstructure evolution leads to poor cycle retention in N884. In contrast, single-crystal particles, free of grain boundaries, synthesized at this critical temperature exhibit superior cycle retention, underscoring the significance of microstructural design over crystalline quality for achieving long-term cyclability. Our study sheds light on the interplay between calcination temperature and microstructural evolution, proposing the critical temperature as a key criterion for single-crystal synthesis."
Could High-Temperature Single Crystals Enable Electric Vehicles Capable of Traveling Up to One million Kilometers? (original news release)
The two ladies are the lead researchers on this paper
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