Impact of Nanoscale Lithium Nickel Manganese Cobalt Oxide (NMC) on the Bacterium Shewanella oneidensis MR-1

Abstract

Nickel manganese cobalt oxide (NMC) comprises a class of lithium intercalation compounds with the composition L x Ni y Mn z Co 1-y-z O 2 (0 < x,y,z < 1). These compounds are of emerging importance in nanoparticle form as cathode materials for lithium-ion batteries used in transportation and consumer electronics. To evaluate the potential environmental impact of release of this material in the environment, we synthesized NMC nanosheets and investigated their interaction with Shewanella oneidensis, a soil and sediment bacterium. Exposure to 5 mg/L NMC significantly impaired bacterial population growth and respiration. Measurements of NMC surface composition by X-ray photoelectron spectroscopy and of the composition of the suspending solution via inductively coupled plasma-optical emission spectroscopy (ICP-OES) demonstrated incongruent material dissolution and measurable release of all four metal constituents (Li, Mn, Co, and Ni) into solution. Speciation modeling and assessment of bacterial response to metal ion exposure (via cell growth and respiration measurements) established that the observed bacterial inhibition arose from the metal ions released from the NMC, with the largest effects arising from Ni(II) and Co(II) species.

Core chemistry influences the toxicity of multicomponent metal oxide nanomaterials, lithium nickel manganese cobalt oxide, and lithium cobalt oxide to Daphnia magna

“…Samples for SEM images were prepared by spin‐coating (1000 rpm) a dilute methanolic solution of either NMC or LiCoO 2 onto a pristine boron‐doped SiO 2 wafer. For transmission electron microscopy images of NMC and LCO, see Dogangun et al and Hang et al , respectively.…”

“…Only a few studies have highlighted the toxicological implications and mode of action of these nanoscale complex metal oxides. A prior study of LCO nanosheets and supported lipid bilayers showed that this material had the ability to alter synthetic bilayer compositional symmetry ; in bacteria, toxicity was the result of dissolution of Ni and Co ions . The impact of nanoscale LCO and NMC on multicellular organisms is largely unknown.…”

DFT and Thermodynamics Calculations of Surface Cation Release in LiCoO2

“…To further characterize the bulk structure, we performed an experimental Raman study and a computational vibrational analysis. The Raman spectrum of bulk LCO in the range 400 -700 cm −1 is shown in Figure 3b surface being predominant as shown by experiments 10,16 and DFT calculations. 29 Moreover, first-principles thermodynamics 13 show that the LCO(001) surface exhibits two distinct ter- In order to build structural models for the surface, two base unit cells were used.…”

DFT and thermodynamics calculations of surface cation release in LiCoO2

“…8,9 The prototypical electroactive CMO used in Li-ion batteries is LiCoO 2 (LCO), with production and use projected to increase. 10 With no established economic incentive to recycle LCO-based batteries, 11 they can contribute to electronic waste in landfills. 12 When exposed to different environmental conditions, CMO nanomaterials undergo transformations that are only beginning to be explored, [13][14][15][16][17] and which could have as-yet unknown biological impacts.…”

“…Such a scheme was recently applied in the case of binary metal oxide materials, 24,25 where high-throughput experimental works were used to inform hazard and O 2 (NMC) 17 will partially dissolve in aqueous media, releasing transition metals such as Co and Ni to solution. The metals released from these CMOs have shown toxicity effects in Shewanella oneidensis MR-1 bacteria, 10,16 the eukaryotic water flea Daphnia magna, 26 and have also been shown to potentially impact the lipid ordering in model cell membranes. 27,28 The mechanism for the release of metals from NMC has been studied with experimental and density functional theory (DFT) methods.…”