A lithium-ion battery based on a graphene nanoflakes ink anode and a lithium iron phosphate cathode (1403.2161v1)

Abstract: Li-ion rechargeable batteries have enabled the wireless revolution transforming global communication. Future challenges, however, demands distributed energy supply at a level that is not feasible with the current energy-storage technology. New materials, capable of providing higher energy density are needed. Here we report a new class of lithium-ion batteries based on a graphene ink anode and a lithium iron phosphate cathode. By carefully balancing the cell composition and suppressing the initial irreversible capacity of the anode, we demonstrate an optimal battery performance in terms of specific capacity, i.e. 165 mAhg-1, estimated energy density of about 190 Whkg-1 and life, with a stable operation for over 80 charge-discharge cycles. We link these unique properties to the graphene nanoflake anode displaying crystalline order and high uptake of lithium at the edges, as well as to its structural and morphological optimization in relation to the overall battery composition. Our approach, compatible with any printing technologies, is cheap and scalable and opens up new opportunities for the development of high-capacity Li-ion batteries.

• The paper introduces a graphene nanoflakes ink anode that achieves a reversible capacity of 165 mAh/g over 80 cycles.
• It employs ultracentrifugation to sort graphene nanoflakes, optimizing morphology and enhancing lithium ion storage via increased active sites.
• The study showcases a scalable and cost-effective production method, paving the way for improved energy density in practical Li-ion battery applications.

Exploration of a Graphene Nanoflakes Ink Anode in Lithium-Ion Battery Systems

The advent of lithium-ion (Li-ion) batteries has revolutionized portable electronics and electric vehicles. However, contemporary energy demands push the boundaries of current battery technology, necessitating the exploration of more effective energy storage solutions. This paper introduces a novel approach utilizing graphene nanoflakes ink for the anode, coupled with a lithium iron phosphate cathode, in lithium-ion batteries.

Key Contributions

The research demonstrates the fabrication and performance of a Li-ion battery using graphene nanoflakes ink as the anode material. The authors effectively address the prevalent challenges of high specific capacity and energy density, achieving a reversible specific capacity of 165 mAh/g and operating over 80 charge-discharge cycles. This performance correlates with the structural optimization of the graphene anode, which possesses high crystallinity and an abundance of active sites for lithium uptake.

Insights into Electrode Materials

Graphene nanoflakes, derived from liquid-phase exfoliation of graphite, offer advantageous properties for anode applications in Li-ion batteries. Their small lateral size and high edge-to-bulk ratio of carbon atoms enable enhanced lithium ion storage capabilities. The paper highlights the use of ultracentrifugation for sorting nanoflakes, which contributes to controlling their morphological properties and, consequently, optimizing their electrochemical performance.

Electrochemical Performance and Optimization

Through rigorous electrochemical testing, the paper documents an impressive specific capacity reaching ~7500 mAh/g during the initial discharge, attributable in part to side reactions forming solid electrolyte interphases. Subsequent ex-situ lithiation processes effectively mitigate these issues, optimizing cycle life and coulombic efficiency. The paper showcases the potential of ultra-light and scalable graphene nanoflakes for achieving higher energy densities in comparison with traditional graphite anodes.

Practical Implications and Future Directions

The implications of employing graphene nanoflakes ink in anode construction are multifaceted. The scalability and cost-effectiveness of the production process, compatible with existing printing technologies, present a viable path towards high-capacity Li-ion batteries. The results promote the use of graphene nanoflakes in energy storage, suggesting further research into assembling these materials with various cathode systems and exploring their roles in novel energy devices such as Li-air batteries and supercapacitors.

Conclusion

In conclusion, this research offers substantial contributions to the field of battery technology, with the development of a graphene nanoflakes-based anode opening avenues for significant improvements in energy storage capabilities. This work stands as pivotal in advancing the scope of Li-ion batteries, aligning with the objective of meeting future energy demands more sustainably and efficiently. Continued exploration of graphene materials promises further enhancements in battery performance and applicability.