Two-Dimensional Layered Materials for Battery Application--Yifei Li

Yifei Li Materials Science and Engineering Program

Department of Electrical and Computer EngineeringUniversity of Houston

To those who may concern

Contents

1. Introduction1.1. Introduction of LIB1.2. Beyond LIB

2. 2D materials for LIB and beyond2.1. 2D layered graphite as anode2.2. 2D layered dichalcogenides2.3. 2D layered AxMOy oxide materials2.4. Other 2D oxide electrode materials

3. Novel electrode design for enhanced battery performance

3.1. MoS2-PEO nanocomposites

3

1. Introduction1.1Introduction of LIB (Lithium Ion Battery)

Figure 1. (a) Movement of Li+ in an electrolyte and insertion-extraction of Li+ within electrodes in a lithium secondary battery. (b) Illustrative voltage curves as a function of state of charge of a battery for charging and discharging cycles at constant current.

a b

Annu. Rev. Chem. Biomol. Eng. 2012. 3:445–71

Figure 2. (a) Cylindrical lithium secondary batteries. (b) A comparison of the energy andpower densities of common rechargeable batteries. Li-ion batteries are superior to theothers.

a b

1.2 Motivation for Beyond LIB1.2.1 Low-cost, Earth Abundant Cations

5

Lithium Sodium Magnesium

Gravimetric Capacity (mAh g-1) 3861 1166 2205 Volumetric Capacity (mAh cm-3) 2066 1128 3833 Potential (V vs NHE) −3.04 −2.71 −2.372 Global Production (kg yr-1) 2.5×107 (very low) 1010 (high) 6.3×109 (high) Price (carbonate; $ ton-1) 5000 200 600 Mn+ Radius (Å) 0.68 0.95 0.65 Polarization Strength (105/pm-2) 21.6 11.1 47.3

2. 2D materials for LIB and beyond2.1 2D layered graphite as anode

Figure 3. (a) Schematic drawing of the crystal structure ofhexagonal graphite, showing the AB layer stacking sequence andthe unit cell. (b) Constant current charge/discharge curves (1st and2nd cycle) of the graphite.

Adv. Mater. 1998, 10, No. 10

a b

𝐴𝐴 = 𝜋𝜋𝑟𝑟2

2.2. 2D layered dichalcogenides

Figure 4. (a) The two-dimensional crystal structures of TiS2, MoS2, and NbS2. (b) Discharge/charge curveof Li/TiS2 at 10 mA/cm2. (c) Electrochemical insertion of lithium into VSe2.

Chemical Reviews, 2004, Vol. 104, No. 10

TiS2

Adv. Mater. 1998, 10, No. 10

a

b c

Staging Effect

S. M. Whittingha. Intercalation chemistry. Elsevier, 2012.

Staging Effect in TiS2

J. Electrochem. Soc. 127 (1980) 2097-2099Electrochim. Acta 50 (2005) 2927-2932

Na-TiS2

Figure 5. (a) Alkali metal intercalation compounds of TiS2. (b) Cell emf during primary discharge and first recharge.

2.3. 2D layered AxMOy oxide materials

LiCoO2:First successful commercialized LIB usingLiCoO2 as cathode and carbon as anode, bySONY in 1990. It dominated the lithiumbattery Market for about 20 years.

Sony Corporation, Battery Group, Solid State Ionics 69 (1994) 212-221

Figure 6 . Crystal structures of various NaxMOy : (a) P2-NaxCoO2, (b) O3-NaxCoO2, (c) P3-NaxCoO2.

Electrochemistry Communications 12 (2010) 355–358

NaCrO2

P2-Na2/3Co2/3Mn1/3O2

Dalton Trans., 2011, 40, 9306–9312

P2-Nax[Fe1/2Mn1/2]O2 O3-Nax[Fe1/2Mn1/2]O2

Figure 7. a,b, Galvanostatic charge/discharge(oxidation/reduction) curves for Na/NaFe1/2Mn1/2O2 (a)and Na-Na2/3TFe1/2Mn1/2O2 (b) cells at a rate of 12mAg-1in the voltage range of 1.5 and 4.3V. (c) Comparison of thedischarge capacity retention of the sodium cells.

Nature Materials, 11, 512–517 (2012)

2.4. Other 2D oxide electrode materials

ACS Nano, 2012, 6 (1), pp 530–538

Bilayered V2O5

V2O5·nH2O for Na ion battery

Figure 8. SIB performance of the V2O5·nH2O cathode. CV curves (a) and discharge–charge curves at current density of 0.1 A g1 (b). Cycling performance at the current density of 0.1 A g1 (c) and the rate performance (d).

J. Mater. Chem. A, 2015,3, 8070-8075

J. Electrochem. Soc. 1993, 140, 140.

V2O5 used in Mg ion battery

V2O5

Shielding Effect

Mo6S8

Mo6S8 is the most successful MIB cathode material, which has plateau and moderate capacity.

Graphene based hybrid electrode materials

Adv. Mater. 2012, 24, 4097–4111

Figure 9. (a) Growth of self-Assembled (rutile and anatase TiO2 − FGS nanostructured hybrids stabilized by Anionic Sulfate Surfactant; (b) Specific capacity of control rutile TiO2 and the rutile TiO2− FGS hybrids at different charge/discharge rates; (c) Specific capacity of control anatase TiO2 and the anatase TiO2 − FGS hybrids at different charge/discharge rates.

Table 2. Capacities and rate performance of high-capacity oxide/graphene hybrids. Adv. Mater. 2012, 24, 4097–4111

Challenges for NIB (Na Ion Battery) and MIB (Mg Ion Battery)

Inorganic Chemistry, Vol. 46, No. 8, 2007

Na0.44MnO2

NIB: • Capacity decay due to large Na+

• Many phases transitionsMIB:• Sluggish diffusion due to high polarization• Mg2+ passivation film on Mg anode• Very few suitable electrolytes

3. Novel electrode design for enhanced battery performance

Electrode Design for NIB and MIB

Figure 10. With the increase of interlayer distance of MoS2, the interaction between cations and the negatively charged S atoms host weakens, and the spacing to afford larger Na+ and polarized Mg2+ is enlarged. So the intercalation and diffusion for both Na+ and Mg2+ will be facilitated.

3.1 MoS2-PEO Nanocomposites

3.1.1 Materials ConsiderationMoS2 A layered transition-metal dichalcogenide. MoS2 layers are held by van der Walls interactions. So guest molecules

may have chance to get intercalated. A range of MoS2−PEO intercalate composites have already been

documented, allowing for a precise tuning of the interlayer distance.

Pillar Molecule: Polyethylene oxide (PEO) PEO is a solid-state Li+, Na+ and Mg2+ conductor. PEO is flexible and water dissolved, so PEO can be intercalated into the

host in aqueous solution. MoS2-PEO and MoO3-PEO composites have been documented.

MoS2

Figure 11. (a) Synthesis of interlayer expanded MoS2 composites. (a) (b,c,d,e) TEM images of com-MoS2, res-MoS2, peo1- MoS2, and peo2-MoS2, respectively.

Yanliang Liang, Hyun Deog Yoo, Yifei Li and Yan Yao, Nano Lett. 2015, 15, 2194−2202

3.3.2 Materials Characterization for MoS2

Figure 12. (a) XRD spectra and (b) TGA analysis of com-MoS2, restacked-exfoliated (re)-MoS2, PEO1L-MoS2 and PEO2L-MoS2.

a b

3.3. Mg-Ion Battery of MoS2

Figure 13. Performance of Li and Mg cells with the MoS2 samples as working electrode. (a) Discharge−chargeprofile of Li cells. (b) Discharge−charge profile of Mg cells with 0.25 M all-phenyl complex (APC) electrolyteand Mg metal as counter and reference electrodes. (c) Cycling stability at higher current densities. (d)Normalization and comparison of the capacity retention at different current densities.

Conclusions

1. Due to the high cost, difficult for large scale applicationand dendrite formation on Li anode, new candidatesare needed to compete with Li ion battery. Na and Mgion batteries thus have their potential application.

2. Two dimensional materials have been employed all thetime with the development of LIB, from graphite, TiS2 toLiCoO2.

3. 2D layered materials are even more beneficial in NIBand MIB.

4. Interlayer distance expansion strategy is a novel way toaddress the issue of Na and Mg in 2D materials. MoS2-PEO composite is introduced as a model material.