NU 2015-088

Inventors

Laila Jaber Ansari

Kanan Puntambekar

Michael Thackery

Mark Hersam*

Short Description

Graphene coating of spinel-structured Lithium Manganese Oxide cathodes that lower the cost of batteries while increasing its lifetime, efficiency and capacity.

Abstract

Northwestern researchers have identified a solution that improves lithium battery life and capacity using the desirable cathode, spinel-structured LiMn2O4 (LMO). LiCoO2 cathodes are currently a more popular consumer battery but have a relatively short life span, limited load capacities and are thermally less stable. LMO, more commonly used in transportation applications, is a desirable cathode material due to its low cost, abundance, and high power capability. However, LMO suffers from a limited cycle life due to manganese dissolution into the electrolyte during electrochemical cycling. Northwestern researchers have shown that single-layer graphene coatings can suppress the dissolution of manganese, thus enhancing the performance and lifetime of spinel LMO cathodes. Compared to lithium battery cells containing an uncoated LMO cathode, cells with a graphene-coated LMO cathode provide improved capacity retention with enhanced cycling stability and rate capability and uncompromised surface conductivity. X-ray photoelectron spectroscopy depth profiling reveals that the graphene coating inhibits manganese depletion from the LMO cathode. Additionally, cross-sectional transmission electron microscopy demonstrates that the graphene coatings are an atomically thin and dense solid electrolyte interphase on the cathode surface. This method for coating LMO cathodes facilitates the application of low-cost and environmentally friendly LMO cathodes in lithium batteries and can potentially reduce the cost of lithium ion batteries while increasing the battery lifetime and efficiency.

Applications

• Lithium ion batteries for portable electronics, electric vehicles, etc.

Advantages

• Lower Cost
• Environmentally Friendly
• Improved battery lifetime, efficiency and capacity
• Selective diffusion of manganese ions
• Well-defined thin and uniform graphene layer with uncompromised conductivity

Publications

Jaber-Ansari L, Puntambekar K, Kim S, Aykol M, Luo L, Wu J, Myers B, Iddir H, Russell J, Saldana S, Kumar R, Thackeray M, Curtiss L, Dravid V, Wolverton C, and Hersam M (2015) Suppressing Manganese Dissolution from Lithium Manganese Oxide Spinel Cathodes with Single-Layer Graphene. Advanced Energy Materials. 5(17), 1500646(1-10).

IP Status

US Provisional Patent Filed