Keeping a clean path: Doubling the capacity of solid-state lithium batteries

January 25, 2021

Scientists at Tokyo Institute of Technology (Tokyo Tech), Tohoku University, National Institute of Advanced Industrial Science and Technology, and Nippon Institute of Technology, demonstrated by experiment that a clean electrolyte/electrode interface is key to realizing high-capacity solid-state lithium batteries. Their findings could pave the way for improved battery designs with increased capacity, stability, and safety for both mobile devices and electric vehicles.

Liquid lithium-ion batteries are everywhere, being found in the majority of everyday mobile devices. While they possess a fair share of advantages, liquid-based batteries carry notable risks as well. This has become clear to the public in recent years after reports of smartphones bursting into flames due to design errors that caused the battery's liquid electrolyte to leak and catch fire.

Other disadvantages such as fabrication cost, durability, and capacity, led scientists to look into a different technology: solid-state lithium batteries (SSLBs). SSLBs comprise solid electrodes and a solid electrolyte that exchange lithium (Li) ions during charging and discharging. Their higher energy density and safety make SSLBs very powerful sources.

However, there are still many technical challenges preventing SSLBs' commercialization. For the current study, researchers conducted a series of experiments and gained insight that could take SSLBs' performance to the next level. Professor Taro Hitosugi from Tokyo Tech, who led the study, explains their motivation: "LiNi0.5Mn1.5O4 (LNMO) is a promising material for the positive electrode of SSLBs because it can generate comparatively higher voltages. In this study, we showed battery operations at 2.9 and 4.7 V, and simultaneously achieved large capacity, stable cycling, and low resistance at the electrolyte/electrode interface."

Previous studies had hinted that producing a clean electrolyte/electrode interface was essential to achieve low interface resistance and fast charging in LNMO-based SSLBs. Scientists also noted that Li ions spontaneously migrated from Li3PO4 (LPO) electrolyte to the LNMO layer upon fabrication, forming a Li2Ni0.5Mn1.5O4 (L2NMO) phase in LNMO with unknown distribution and impact on battery performance.

The team investigated what the L2NMO phase was like, analyzing the changes in crystalline structure between the Li0Ni0.5Mn1.5O4 (L0NMO) and L2NMO phases during charging and discharging. They also studied the initial distribution of L2NMO at clean LPO/LNMO interfaces fabricated in a vacuum, as well as the effect of electrode thickness.

Strikingly, the clean interface facilitated the intercalation and deintercalation of Li during charging and discharging of the SSLBs. As a result, the capacity of SSLBs with a clean interface was twice that of conventional LNMO-based batteries. Moreover, this study marked the first time stable reversible reactions were found between the L0NMO and L2NMO phases in SSLBs.

Assistant Professor Hideyuki Kawasoko of Tohoku University and lead author of the study remarked, "Our findings indicate that the formation of a contamination-free, clean LPO/LNMO interface is key to increasing the capacity of SSLBs while ensuring low interface resistance for fast charging."

Aside from mobile devices, SSLBs could find a home in electric cars, for which cost and battery durability act as major barriers for widespread commercialization. The results of this study provide important insight for future SSLB designs and pave the way for a transition away from fossil fuels and towards more ecofriendly ways of transportation. Keep an eye out for the advent of SSLBs!
-end-
About Tokyo Institute of Technology

Tokyo Tech stands at the forefront of research and higher education as the leading university for science and technology in Japan. Tokyo Tech researchers excel in fields ranging from materials science to biology, computer science, and physics. Founded in 1881, Tokyo Tech hosts over 10,000 undergraduate and graduate students per year, who develop into scientific leaders and some of the most sought-after engineers in industry. Embodying the Japanese philosophy of "monotsukuri," meaning "technical ingenuity and innovation," the Tokyo Tech community strives to contribute to society through high-impact research.

https://www.titech.ac.jp/english/

About Tohoku University

For more than a century, Tohoku University has been consistently ranked amongst the top academic institutions in Japan. Its research achievements and contributions, coupled with its wide network of collaborative partners, led to it being one of the first institutions to be conferred the status of a Designated National University by the Japanese government in June 2017. The university prides itself in its community engagement and the transformational impacts its research has on society at large. In the aftermath of the 2011 Great East Japan Earthquake, Tohoku University pioneered research in next-generation medicine and disaster science, giving local and global communities the necessary tools and knowledge to fight illnesses and be better prepared for natural disasters.

http://www.tohoku.ac.jp/en/

National Institute of Advanced Industrial Science & Technology (AIST)

AIST is the largest public research institute established in 1882 in Japan. The research fields of AIST covers all industrial sciences, e.g., electronics, material science, life science, metrology, etc. Our missions are bridging the gap between basic science and industrialization and solving social problems facing the world. we prepare several open innovation platforms to contribute to these missions, where researchers in companies, university professors, graduated students, as well as AIST researchers, get together to achieve our missions. The open innovation platform established recently is The Global Zero Emission Research Center which contributes to achieving a zero-emission society collaborating with foreign researches.

https://www.aist.go.jp/index_en.html

About Nippon Institute of Technology

Nippon Institute of Technology celebrated its 50th anniversary in 2017. Our mission was, and still is, to raise outstanding engineers who can utilize theoretical concepts of engineering in the frontline of industry. We developed our unique teaching method using "practical engineering", making the best use of what students had learnt in technical high school.

https://www.nit.ac.jp/english

Tokyo Institute of Technology

Related Mobile Devices Articles from Brightsurf:

How mobile apps grab our attention
Aalto University researchers alongside international collaborators have done the first empirical study on how users pay visual attention to mobile app designs.

No association found between exposure to mobile devices and brain volume alterations in adolescents
New study of 2,500 Dutch children is the first to explore the relationship between brain volume and different doses of radiofrequency electromagnetic fields

Mobile devices blur work and personal privacy raising cyber risks, says QUT researcher
Organisations aren't moving quickly enough on cyber security threats linked to the drive toward using personal mobile devices in the workplace, warns a QUT privacy researcher.

Multi-mobile (M2) computing system makes android & iOS apps sharable on multiple devices
Computer scientists at Columbia Engineering have developed a new computing system that enables current, unmodified mobile apps to combine and share multiple devices, including cameras, displays, speakers, microphones, sensors, and GPS, across multiple smartphones and tablets.

The use of mobile phone and the development of new pathologies
Professor Raquel Cantero of the University of Malaga (UMA) has identified a generational change in the use of this finger due to the influence of new technologies.

Mobile devices don't reduce shared family time, study finds
The first study of the impact of digital mobile devices on different aspects of family time in the UK has found that children are spending more time at home with their parents rather than less -- but not in shared activities such as watching TV and eating.

Mobile, instant diagnosis of viruses
In a first for plant virology, a team from CIRAD recently used nanopore technology to sequence the entire genomes of two yam RNA viruses.

Wearable devices and mobile health technology: one step towards better health
With increasing efforts being made to address the current global obesity epidemic, wearable devices and mobile health ('mHealth') technology have emerged as promising tools for promoting physical activity.

Mobile health devices diagnose hidden heart condition in at-risk populations
New research shows wearable mobile health devices improved the rate of diagnosis of a dangerous heart condition called atrial fibrillation.

Ultrasound-firewall for mobile phones
Mobile phones and tablets through so-called audio tracking, can be used by means of ultrasound to unnoticeably track the behaviour of their users: for example, viewing certain videos or staying in specific rooms and places.

Read More: Mobile Devices News and Mobile Devices Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.