Effects of Doping on Lithium Rich NMC Cathode Prepared Via Spray Pyrolysis
The layered lithium-nickel-manganese-cobalt oxides, such as Li1.2Mn0.54Ni0.13Co0.13O2 or 0.5 NMC are known to demonstrate a voltage fade over cycling. This effect has been attributed to a layered-spinel transformation (4). This study will focus on doping Li1.2Mn0.54Ni0.13Co0.13O2using trace level dopants and exploring their effects on voltage fade and cycling stability.
Figure 1 shows a typical SEM result of lithium rich material prepared via spray pyrolysis, demonstrating the uniform and spherical morphology. Figure 2 compares the effect of synthesis method for dopant free material synthesized via co-precipitation and spray pyrolysis, indicating distinct advantages both in terms of capacity and voltage fade for the material synthesized via spray pyrolysis, due to the superior uniformity of the synthesis method (5-7). Figure 3 shows the cycle test results for 0.5 NMC with Al doping. Al doping clearly improves the cycle stability of the sample.
The authors are grateful to the NSF and X-tend Energy LLC for support. RLA and Washington University may receive income based on a license of related technology by the University to X-tend Energy LLC.
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