Skip to main content
Log in

Improved electrical transport properties and optimized thermoelectric figure of merit in lithium-doped copper sulfides

  • Published:
Rare Metals Aims and scope Submit manuscript

Abstract

Copper sulfide Cu2S is a p-type semiconducting compound that has attracted great attentions in the thermoelectric (TE) community most recently. Considering the intrinsic ultralow lattice thermal conductivity, the enhancement of TE performance in Cu2S should be achieved through improving its electrical transport properties. To achieve this goal, lithium element was doped into Cu2S in this study. A series of Cu2−xLi x S samples with different Li contents (x = 0, 0.005, 0.010, 0.050, and 0.100) was synthesized by the melting–annealing method. When x ≤ 0.05, the Cu2−xLi x S samples are stable and pure phases, having the same monoclinic structure with the pristine Cu2S at room temperature. The electrical conductivities in the Cu2−xLi x S samples are greatly improved with the Li-doping content increasing due to the enhanced carrier concentrations. Meanwhile, doping Li into Cu2S increases the ionic activation energy and lessens the influence of mobile Cu ions on the heat-carrying phonons. Thus, the thermal conductivities of the Li-doped Cu2S samples increase. A maximal figure of merit (zT) of 0.84 at 900 K is obtained in Cu1.99Li0.01S, about 133% improvement as compared with that in Cu2S matrix.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

References

  1. Snyder GJ, Toberer ES. Complex thermoelectric materials. Nat Mater. 2008;7(2):105.

    Article  Google Scholar 

  2. Li Z, Xiao C, Zhu H, Xie Y. Defect chemistry for thermoelectric materials. J Am Chem Soc. 2016;138(45):14810.

    Article  Google Scholar 

  3. Zeier WG, Zevalkink A, Gibbs ZM, Hautier G, Kanatzids MG, Snyder GJ. Thingking like a chemist: intuition in thermoelectric materials. Angew Chem Int Ed. 2016;55(24):6826.

    Article  Google Scholar 

  4. Shi X, Chen LD, Uher C. Recent advances in high-performance bulk thermoelectric materials. Int Mater Rev. 2016;61(6):379.

    Article  Google Scholar 

  5. Roy P, Srivastava SK. Nanostructured copper sulfides: synthesis, properties and applications. CrystEngComm. 2015;17(41):7801.

    Article  Google Scholar 

  6. Jiang QH, Yan HX, Khaliq J, Shen Y, Simpson K, Reece MJ. Enhancement of thermoelectric properties by atomic-scale percolation in digenite Cu x S. J Mater Chem A. 2014;2(25):9486.

    Article  Google Scholar 

  7. Chakrabarti DJ, Laughlin DE. The Cu–S (copper–sulfur) system. Bull Alloy Phase Diagr. 1983;4(3):254.

    Article  Google Scholar 

  8. Will G, Hinze E, Abdelrahman ARM. Crystal structure analysis and refinement of digenite, Cu1.8S, in the temperature range 10 to 500 °C under controlled sulfur partial pressure. Eur J Miner. 2002;14(3):591.

    Article  Google Scholar 

  9. He Y, Day T, Zhang TS, Liu HL, Shi X, Chen LD, Snyder GJ. High thermoelectric performance in non-toxic earth-abundant copper sulfide. Adv Mater. 2014;26(23):397.

    Google Scholar 

  10. Zhao KP, Qiu PF, Song QF, Blichfeld AB, Eikeland E, Ren DD, Ge BH, Iversen BB, Shi X, Chen LD. Ultrahigh thermoelectric performance in Cu2−ySe0.5S0.5 liquid-like materials. Mater Today Phys. 2017;1(1):14.

    Article  Google Scholar 

  11. Chen ZW, Jian ZZ, Li W, Chang YJ, Ge BH, Hanus R, Yang J, Chen Y, Huang MX, Snyder GJ, Pei YZ. Lattice dislocations enhancing thermoelectric PbTe in addition to band convergence. Adv Mater. 2017;29(23):1606768.

    Article  Google Scholar 

  12. He Y, Lu P, Shi X, Xu FF, Zhang TS, Snyder GJ, Uher C, Chen L. Ultrahigh thermoelectric performance in mosaic crystals. Adv Mater. 2015;27(24):3639.

    Article  Google Scholar 

  13. Qiu PF, Zhu YQ, Qin YT, Shi X, Chen LD. Electrical and thermal transports of binary copper sulfides Cu x S with x from 1.8 to 1.96. APL Mater. 2016;4(10):104805.

    Article  Google Scholar 

  14. Qiu PF, Zhang TS, Qiu YT, Shi X, Chen LD. Sulfide bornite thermoelectric material: a natural mineral with ultralow thermal conductivity. Energy Environ Sci. 2014;7(12):4000.

    Article  Google Scholar 

  15. Li XY, Hu CG, Kang XL, Len Q, Xi Y, Zhang KY, Liu H. Introducing kalium into copper sulfide for the enhancement of thermoelectric properties. J Mater Chem A. 2013;1(44):13721.

    Article  Google Scholar 

  16. Zhang AJ, Shen XC, Zhang Z, Lu X, Yao W, Dai J, Xie DD, Guo LJ, Wang GY, Zhou XY. Large-scale colloidal synthesis of Cu5FeS4 compounds and their application in thermoelectrics. J Mater Chem C. 2017;5(2):301.

    Article  Google Scholar 

  17. Balapanov MK, Gafurov IG, Mukhamed’yanov UK, Yakshibaev RA, Ishembetov RK. Ionic conductivity and chemical diffusion in superionic Li x Cu2−xS (0 ≤ x ≤ 0.25). Phys Status Solidi B. 2004;241(1):114.

    Article  Google Scholar 

  18. Kang SD, Pöhls JH, Aydemir U, Qiu PF, Stoumpos CC, Hanus R, White MA, Shi X, Chen LD, Kanatzidis MG, Snyder GJ. Enhanced stability and thermoelectric figure-of-merit in copper selenide by lithium doping. Mater Today Phys. 2017;1(1):7.

    Article  Google Scholar 

  19. Potter RW. An electrochemical investigation of the system copper–sulfur. Econ Geol. 1977;72(8):1524.

    Article  Google Scholar 

  20. Shannon RD. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. 1976;A32(5):751.

    Article  Google Scholar 

  21. Kowalczyk SP, Ley L, McFeely FR, Pollak RA, Shirley DA. X-ray photoemission from sodium and lithium. Phys Rev B. 1973;8(8):3583.

    Article  Google Scholar 

  22. Duan B, Yang J, Salvador JR, He Y, Zhao B, Wang SY, Wei P, Ohuchi FS, Zhang WQ, Hermann RP, Gourdon O, Mao SX, Cheng YW, Wang CM, Liu J, Zhai PC, Tang XF, Zhang QJ, Yang JH. Electronegative guests in CoSb3. Energy Environ Sci. 2016;9(6):2090.

    Article  Google Scholar 

  23. Marshall R, Mitra SS. Optical properties of cuprous sulfide. J Appl Phys. 1965;36(12):3882.

    Article  Google Scholar 

  24. Jiang BB, Qiu PF, Eikeland E, Chen HY, Song QF, Ren DD, Zhang TS, Yang J, Iversen BB, Shi X, Chen LD. Cu8GeSe6-based thermoelectric materials with an argyrodite structure. J Mater Chem C. 2017;5(4):943.

    Article  Google Scholar 

  25. Zhao KP, Duan HZ, Raghavendra N, Qiu PF, Zeng Y, Zhang WQ, Yang JH, Shi X, Chen LD. Solid-state explosive reaction for nanoporous bulk thermoelectric materials. Adv Mater. 2017;29(42):1701148.

    Article  Google Scholar 

  26. He Y, Zhang TS, Shi X, Wei SH, Chen LD. High thermoelectric performance in copper telluride. NPG Asia Mater. 2015;7(8):e210.

    Article  Google Scholar 

  27. Zhao LL, Wang XL, Fei FY, Wang JY, Cheng ZX, Dou SX, Wang J, Snyder GJ. High thermoelectric and mechanical performance in highly dense Cu2−xS bulks prepared by a melt-solidification technique. J Mater Chem A. 2015;3(18):9432.

    Article  Google Scholar 

  28. Ge ZH, Zhao LD, Wu D, Liu X, Zhang BP, Li JF, He JQ. Low-cost, abundant binary sulfides as promising thermoelectric materials. Mater Today. 2016;19(4):227.

    Article  Google Scholar 

  29. Zhao KP, Blichfeld AB, Chen HY, Song QF, Zhang TS, Zhu CX, Ren DD, Hanus R, Qiu PF, Iversen B, Xu FF, Snyder GJ, Shi X, Chen LD. Enhanced thermoelectric performance through tuning bonding energy in Cu2Se1−xS x liquid-like materials. Chem Mater. 2017;29:6367.

    Article  Google Scholar 

  30. Lukashev P, Lambrecht WRL, Kotani T, van Schilfgaarde M. Electronic and crystal structure of Cu2−xS: full-potential electronic structure calculations. Phys Rev B. 2007;76(19):195202.

    Article  Google Scholar 

  31. Sun YX, Xi LL, Yang J, Wu LH, Shi X, Chen LD, Snyder GJ, Yang JH, Zhang WQ. The “electron crystal” behavior in copper chalcogenides Cu2X (X = Se, S). J Mater Chem A. 2017;5(10):5098.

    Article  Google Scholar 

  32. May AF, Fleurial JP, Snyder GJ. Thermoelectric performance of lanthanum telluride produced via mechanical alloying. Phys Rev B. 2008;78(12):125205.

    Article  Google Scholar 

  33. Zhao KP, Blichfeld AB, Eikeland E, Qiu PF, Ren DD, Iversen BB, Shi X, Chen LD. Extremely low thermal conductivity and high thermoelectric performance in liquid-like Cu2Se1−xS x polymorphic materials. J Mater Chem A. 2017;5(34):18148.

    Article  Google Scholar 

  34. Chen YX, Ge ZH, Yin MJ, Feng D, Huang XQ, Zhao WY, He JQ. Understanding of the extremely low thermal conductivity in high-performance polycrystalline SnSe through potassium doping. Adv Funct Mater. 2016;26(37):6836.

    Article  Google Scholar 

Download references

Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (Nos. 51472262 and 51625205), the Key Research Program of Chinese Academy of Sciences (No. KFZD-SW-421) and the Shanghai Government (No. 15JC1400301).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Peng-Fei Qiu.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Guan, MJ., Qiu, PF., Song, QF. et al. Improved electrical transport properties and optimized thermoelectric figure of merit in lithium-doped copper sulfides. Rare Met. 37, 282–289 (2018). https://doi.org/10.1007/s12598-018-1007-0

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12598-018-1007-0

Keywords

Navigation