Abstract
The high voltage spinel material LiMn1.5Ni0.5O4 (LMNO) has the potential to increase the energy density of lithium batteries. However, its battery performance suffers from poor long-term cycling and high-temperature stability. In order to overcome these limitations, we have studied the effect of partial substitution of Mn with Ti and LiMn1.5−x Ni0.5TixO4 (x = 0.05, 0.1, 0.3), LMNTO, materials have been synthesized in a newly modified sol-gel method and then characterized by TEM, SEM (EDX), AC Electrochemical Impedance Spectroscopy and Soft X-ray Spectromicroscopy. We have demonstrated that the long-term cycling limitation with these types of materials can be resolved and herein 2000 cycles at a high C-rate have been demonstrated in half cells. We have attributed this behavior to a possible charge compensation mechanism as evidenced by a Soft X-ray Spectromicroscopy study of delithiated LMNTO materials. This work takes high energy density batteries based on high voltage spinel material one step further towards commercialization, and it is believed that further improvement can be achieved using new electrolyte formulations.
Highlights
Lithium-ion batteries are currently the dominant power source for many mobile and stationary applications such as consumer electronics, power tools, electric vehicles and electrical grid, there is an ever-increasing demand to further increase the energy and power densities, extend cycle life, enhance safety and lower their cost
The spinel LiMn1.5Ni0.5O4, LMNO, cathode material has been identified as a promising candidate since the discovery that the substitution of the parent spinel LiMn2O4 with Ni from Mn cations shifts the potential of the redox reaction from 4.1 V vs. Li/Li+ related to Mn+3/+4 redox couple to 4.7 V vs. Li/Li+ related to Ni+2/+4 couple
Both materials have been cycled at room temperature and a C-rate of 2.22C for 2000 cycles
Summary
Lithium-ion batteries are currently the dominant power source for many mobile and stationary applications such as consumer electronics, power tools, electric vehicles and electrical grid, there is an ever-increasing demand to further increase the energy and power densities, extend cycle life, enhance safety and lower their cost. One approach to improve the energy density is to increase the operating voltage of the batteries by developing high voltage “positive” cathode materials in combination with the low voltage, conventional graphite anode. Such a development would have the added benefit of facilitating the use of safer, higher voltage anode materials such as Li4Ti5O12 for a safer Liion cell with practical voltage (>3 V). Yi et al [22] have summarized the possible failure modes of LiNi0.5Mn1.5O4 and the key strategies for enhancing the battery performance It was demonstrated by many research groups that long-term cycling especially at higher temperature and rate capability is the main issue.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
