Vol.:(0123456789)1 3

Journal of Applied Electrochemistry https://doi.org/10.1007/s10800-018-1249-4

RESEARCH ARTICLE

A high-performance Te@CMK-3 composite negative electrode for Na rechargeable batteries

Toshinari Koketsu1 · Chao Wu2 · Yunhui Huang2 · Peter Strasser1

Received: 1 May 2018 / Accepted: 6 August 2018 © Springer Nature B.V. 2018

AbstractWe report a new class of high-capacity chalcogen–carbon composite negative electrodes for Na rechargeable batteries, consisting of tellurium-infiltrated ordered mesoporous carbon CMK-3. Its unparalleled electric conductivity makes Te a promising electrode material with high-capacity utilization. The rechargeable cell Na/Te@CMK-3, using a carbonate-based electrolyte, exhibited a large stable capacity of ~ 320 mA h (g-Te)−1 at 0.2 C with an excellent rate capability (55% of the theoretical specific capacity at 2 C-rate), and long-term cyclability (> 500 cycles), as well as 100% coulombic efficiency. Our study evidences the great potential of mesoporous carbon-encapsulated Te materials concepts as a new class of high-performance chalcogen-based electrode materials for Na rechargeable batteries.

Graphical abstract

Keywords Tellurium · Chalcogen · CMK-3 mesoporous carbon · Na-ion battery negative electrode

1 Introduction

Over past decades, the demand for larger scale battery storage devices has increased thanks to new applications in electric vehicles and stationary energy storage devices for renewable energies [1–3]. Conventional as well as Li-ion batteries have been the batteries of choice because of their reliability and safety on the one side, and the high energy density and good cyclability of the latter, on the other. However, with increasing future demand of ever larger scale batteries, potential risks associated with Li supply

Electronic supplementary material The online version of this article (https ://doi.org/10.1007/s1080 0-018-1249-4) contains supplementary material, which is available to authorized users.

* Peter Strasser pstrasser@tu-berlin.de

1 The Electrochemical Energy, Catalysis and Materials Science Laboratory, Department of Chemistry, Technical University Berlin, 10623 Berlin, Germany

2 State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China

Journal of Applied Electrochemistry

1 3

and production and operational safety may grow as well to unacceptable levels [4].

In contrast to Li resources, Na resources are low cost and much more abundant. Besides, the standard elec-trochemical potential of Na (− 2.7 V vs. SHE, Stand-ard Hydrogen Electrode) is only slightly more anodic compared to Li (− 3.04 VSHE) [5–7]. These advantages make Na rechargeable batteries attractive as post-Li-ion rechargeable batteries. At present, various positive elec-trode materials are proposed and investigated, and some of them have already showed promising performance [8, 9]. On the other hand, only a few negative electrode materials are available, and this lack largely hindered the develop-ment of viable commercialized Na rechargeable batter-ies [10]. For instances, a class of carbonaceous materials were useful for Li-ion battery system; however, they are barely active for Na-ion intercalation [11–14]. Therefore, it is necessary to explore new classes of negative electrode materials. This work addresses this unmet scientific and technical challenge.

The members of group 16 elements (chalcogens), with special emphasis on sulfur (S), are currently widely investi-gated as a Na battery electrode material [15–17]. The elec-trochemical reactions of S and Se in Na-ion rechargeable battery system are represented by Eq. (1).

Na/S batteries show an attractive large theoretical capac-ity (1672 mA h g−1 or 3461 mA h cm−3) and high energy density (1262 W h kg−1 or 1685 W h l−1), yet severe techni-cal challenges remain to the practical application. Repre-sentative examples are the extremely low conductivity of S (~ 5.10−30 S cm−1), the high solubility of sodium poly-sulfide in the electrolyte, as well as the pulverization of the electrode upon charge/discharge cycling [18–21]. Here, encapsulation of S in the porous carbon structure (S@C) is considered to be effective strategy to stabilize charge/dis-charge cycling and to extend their cyclability. The second member of the chalcogens, Se@C composite, was reported to show rather good cyclability and rate capability with simi-lar volumetric capacity as a S@C composite electrode. This is explained largely due to their better electrical conductivity (~ 10−3 S cm−1) and larger density (4.8 g cm−3) [22, 23].

Compared with S and Se, the third member of chalcogen, Te, has advantageous physicochemical characteristics such as ultrahigh electrical conductivity (5 S cm−1), and higher density (6.2 g cm−3). Besides, Te@C electrodes have been reported to show the excellent performance in Li recharge-able battery system [24–28]. Although Te@C can be used as a positive electrode material for lithium rechargeable bat-teries, the low working potential of + 1.5 VNa+/Na is rather suitable as a negative electrode material for Na-ion recharge-able batteries (see Table S1). The expected electrochemical

(1)An+ 2n Na

+ + 2n e−⇄ Na2nAn

(A: S, Se).

reaction is the accommodation of 2 Na atoms per a Te atom given by the Eq. (2).

To date, there are few to none in-depth reports on the electrochemical behavior of Te electrodes for Na battery applications [6, 29]. To fill that gap, in this report, we inves-tigate the electrochemical performance of Te infiltrated CMK-3 ordered mesoporous carbon composite (Te@CMK-3) cell in Na battery system. Our results evidence that Te@CMK-3 electrodes offer excellent cycling characteristics for Na-ion rechargeable batteries.

2 Experimental section

2.1 Sample preparation

2.1.1 Mesoporous silica template with hexagonal morphology (SBA-15)

SBA-15 was synthesized according to the previous reports [30]. Briefly, poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) tri-block copolymer (2.0 g, EO20PO70EO20, BASF) was dissolved into a hydrochloric acid (2 M, 60 ml) and the temperature of the solution was controlled to be 38 °C. Tetraethylorthosilicate (4.2 g, 98%, Aldrich) was dropped into the solution and it was stirred for 6 min. Then, it was in a quiescent for 24 h followed by heat-ing at 95 °C for 24 h using an autoclave. White deposits were separated and calcined at 550 °C in the air for 6 h.

2.1.2 Ordered mesoporous carbon (CMK-3)

SBA-15 (1.0 g) was dispersed in H2SO4 aqueous solution (5 ml, 28 g l−1) containing sucrose (1.25 g). The solution was stepwisely heated in the air at 100 °C for 2 h and then at 160 °C for 12 h [31, 32]. After repeating this process again with H2SO4 aqueous solution (5 ml, 16 g l−1) containing sucrose (0.80 g), the solution was heated at 900 °C for 5 h under N2 flow. CMK-3 was obtained by dissolving SBA-15 using 1 M NaOH aqueous solution at 80 °C for 12 h.

2.1.3 Te infiltrated CMK-3 (Te@CMK-3) composite

Melt Te (100 mg, 99.8%, Sigma Aldrich) was infiltrated into 50 mg of CMK-3 mesoporous carbon by heating in a closed vessel under Ar flow atmosphere at 550 °C for 6 h [25]. Na2Te powder (99.9%, Strem Chemicals) was used without any treatment to test the reactivity in the solvents.

(2)Ten+ 2n Na

+ + 2n e−⇄ Na2nTen.

Journal of Applied Electrochemistry

1 3

2.2 Physicochemical characterization

X-ray powder diffraction (XRD) patterns were collected on D8-Advance diffractometer Bruker AXS (Cu-Kα, λ = 1.5406 Å). Scanning electron micrograph were collected on a field-emission scanning electron microscope (SEM, JEOS JSM 7401F), and transmission electron micrograph and selected area electron diffraction patterns (SAED) were collected on a transmission electron microscope (TEM, FEI Tecnai™ G2 20 S-TWIN) to visually observe morpholo-gies, particle sizes, and elemental distribution over the composite. Nitrogen absorption and desorption isotherms at 77.3 K were collected on Autosorb-1 (Quantachrome Instruments) to calculate the surface area and pore volumes by Brunauer–Emmett–Teller (BET) analysis. Inductively coupled plasma atomic emission spectra (ICP-AES) were collected on Agilent Varian 715-ES to quantify infiltrated Te in the composite electrode. Te was chemically dissolved from Te@CMK-3 composite using hot concentrated sulfuric acid (99.999%, Aldrich) at 150 °C for 12 h.

2.3 Electrochemical characterization

A working electrode was composed of 70 wt% Te@CMK-3, 20 wt% carbon (SuperP, Timcal), and 10 wt% sodium alginate (Aldrich) aqueous binder [33, 34]. These mixtures were dissolved into Milli-Q water and hand-milled using a mortar, and then the slurry was casted on Al foil. The dried electrode was cut into 0.80-cm-diameter pieces and used as the working electrode. Areal theoretical capacity was around 0.1 mA h cm−2. A Te electrode was prepared by mixing 80 wt% Te powder (Sigma Aldrich), 10 wt% carbon

(SuperP, Timcal), and 10 wt% poly(tetrafluoroethylene) (PTFE, beads, Aldrich) using the mortar and pressed on Al mesh. 1 M NaClO4 (> 98%, Aldrich) dissolved in a mix-ture of ethylene carbonate (EC, anhydrous, 99% Aldrich) and propylene carbonate (PC, anhydrous, > 99%, Aldrich) by the volume ratio of 1:1 was used as a carbonate-based electrolyte. 1 M sodium bis(trifluoromethanesulfonyl)amide (NaTFSA, 99.5%, Solvionic) dissolved in tetraethylene gly-col dimethyl ether (tetraglyme, > 99%, Aldrich) was used as an ether-based electrolyte. Borosilicate glass fiber filter paper (Whatman® Grade GF/A) was used as a separator. Na metal plates (> 99.8%, Aldrich) were used as a reference electrode and a counter electrode. Electrochemical meas-urements were carried out at room temperature using three-electrode Swagelok®-type cells assembled in an Ar-filled glove box. C-rate was calculated based on the theoretical specific capacity of Te [420 mA h (g-Te)−1] and the cut-off voltages were + 0.7 and + 3.0 VNa+/Na.

3 Results and discussion

Te@CMK-3 was synthesized according to the previous reports [25, 35, 36]. Figure 1a illustrates the preparation steps of Te@CMK-3 composite from SBA-15 mesoporous silica. Figure S1 shows the SEM images of SBA-15 and CMK-3. With the infiltration of Te into CMK-3, its surface area decreased from 1231 to 70 m2 g−1, and its cumula-tive pore volume was decreased from 1.41 cm3 g−1 to mere 0.08 cm3 g−1 (see Fig. 1b), proving the infiltration of Te into the pores of CMK-3. X-ray diffraction (XRD) patterns in Fig. 1c evidence the formation of a superimposed diffraction

Fig. 1 a A synthetic route of the Te@CMK-3 composite. b Nitrogen adsorption/desorp-tion isotherms and pore size distribution of CMK-3 and Te@CMK-3 composite. c XRD patterns of CMK-3 and Te@CMK-3 composite (diffraction angle: 10° ≦ 2θ ≦ 80°, scan rate: 0.02° s−1), and a reference pat-tern [37]

Journal of Applied Electrochemistry

1 3

patterns, indicating a Te@CMK-3 composite with a residual crystalline phase. The amount of Te after infiltration was determined to be 55 wt% using ICP-AES.

Te@CMK-3 composite has homogeneous distribution of morphology (see Fig. 2a), and Fig. 2b displays a single particle of Te@CMK-3 composite. The dimension of the composite particle was ca. 500 nm, and its back-scattered electron image (see Fig. 2c) showed an even distribution of Te over the CMK-3. TEM images (see Fig. 2d, e) showed the well-ordered CMK-3 structure and the selected area electron diffraction (SAED) image showed no traces of Te phase in this region. Infiltrated Te residuals were visible at the edge

of the composite (see Fig. 2e). The diameter was around 7.6 nm, corresponding to the pore diameter of SBA-15 struc-ture (see Fig. S1). Crystalline Te with the dimension of ca. 200 nm was also observed in another region (see Fig. 2f).

The electrochemical measurements of pure Te and the composite Te@CMK-3 were carried out in Na battery system. Cyclic voltammograms of the Te pure reference electrode (see Fig. S2) showed reduction peaks around 1.1 VNa+/Na, 1.3 VNa+/Na, 1.4 VNa+/Na, and oxidation peaks around + 1.8, + 2.1 VNa+/Na. Those peaks are associated with the redox of Te, forming sodium poly-telluride and Na2Te. A Na/Te three-electrode cell showed a discharge capacity around + 1.1 to + 1.5 VNa+/Na. Those potential range are corresponding to the reduction peaks of the cyclic voltam-mogram. Na2Te salt are partially precipitated on the surface of the electrode, gradually blocking the access to the elec-trochemical active materials. Therefore, the electrochemical activity of the electrode was largely suppressed in the first three charge/discharge cycles.

Cyclic voltammograms for the composite Te@CMK-3 electrode (see Fig. S3) showed two sharp reduction current peaks at + 1.6 VNa+/Na and + 1.4 VNa+/Na. As observed in a Na/S cell [19], those two reduction peaks are the forma-tion of Na2Te2 and Na2Te, respectively. On the other hand, three distinct oxidation current peaks were observed at + 1.6 VNa+/Na, + 1.7 VNa+/Na, and + 2.0 VNa+/Na, indicating the formation of a series of sodium polytellurides (Na2Ten). In 10 cycles, the sharp current peaks evolved into broader sodi-ation/desodiation peaks around + 1.6 VNa+/Na/+ 1.1 VNa+/Na.

Figure 3a shows the charge/discharge curves of a three-electrode cell, Na/Te@CMK-3. A discharge capacity of ca. 900 mA h (g-Te)−1 was obtained in the 1st cycle, and it declined to a stable capacity of 320 mA h (g-Te)−1 after 10 cycles. Those cyclic voltammograms and charge/discharge curves indicate a series of intermediates during both sodia-tion and desodiation process in the initial formation proce-dure. Those compounds are most likely stable in the car-bonate-based electrolyte after the side reaction between Te and the electrolyte has ceased. We have concluded that the

Fig. 2 SEM and TEM images of Te@CMK-3. a An overview image, b high-magnification image, and c its back-scattered electron image of a single Te@CMK-3 particle. d Low-magnification TEM image and a SAED pattern of Te@CMK-3 composite, e its high-magnifica-tion images, and f not infiltrated Te crystal and its SAED pattern

Fig. 3 Charge/discharge curves for a Na/Te@CMK-3 three-electrode cell using either a 1 M NaClO4/EC + PC or b 1 M NaTFSA/tetraglyme as the electrolyte at 0.2 C (cut-off volt-ages: + 0.7 and + 3.0 VNa+/Na)

Journal of Applied Electrochemistry

1 3

sodiation reaction proceeds without intermediate steps after formation procedure, and charge/discharge curves showed gradual transition.

To exclude the possibility of Na-ion insertion into the CCMK-3 scaffold, the electrochemical behavior of a Na/CCMK-3 cell was tested as well (see Fig. S4). A discharge capacity of ca. 200 mA h (g-CCMK-3)−1 was obtained in the 1st cycle. This capacity can be derived from Na-ion intercalation into CMK-3 to neutralize the charges of acidic carbon on the sur-face of CMK-3 formed during the synthesis [38, 39]. After several cycles, double-layer-based capacitance behavior was observed. However, the pore structure of CMK-3 is blocked by the Te infiltration and those non-faradaic capacity can be negligible for the Te@CMK-3 composite electrode.

To reveal the nature and behavior of intermediates dur-ing sodiation/desodiation process, the electrochemical behavior of the composite Te@CMK-3 electrode in the ether-based electrolyte was also examined (see Fig. 3b). A Na/Te@CMK-3 cell using the electrolyte of 1 M NaTFSA in tetraglyme displayed more pronounced electrochemi-cal behavior. The discharge capacity in the 1st cycle was 367 mA h (g-Te)−1, evidencing that an initial side reaction observed in the carbonate-based cell was this time absent. Two potential plateaus at 1.6 VNa+/Na and 1.4 VNa+/Na in the discharge process, and three plateaus at 1.6 VNa+/Na, 1.7 VNa+/Na, and 1.9 VNa+/Na in the charge process were observed. Those are in agreement with the redox potentials observed in the 1st cycle of cyclic voltammogram using the carbonate-based electrolyte. Reversible capacity has contin-uously decreased upon charge/discharge cycling. Figure S5 shows Na2Te powders in EC + PC and Na2Te in tetraglyme. The carbonate-based solution stayed colorless and transpar-ent; on the other hand, the Na2Te and tetraglyme have appar-ently reacted. The degradation of capacity in ether-based electrolyte is most likely due to the instability of Na2Te in ether-based electrolyte.

Rate capability and cyclability of the three-elec-trode Na/Te@CMK-3 cell were evaluated using the

carbonate-based electrolyte after 10 cycles of charge/discharge process to passivate the Te@CMK-3 composite electrode and to arrive at its stable charge/discharge per-formance (see Fig. 4). The Na/Te@CMK-3 cell showed stable charge/discharge capacities over a wide range of C rates. The discharge capacity was 310 mA h (g-Te)−1 at 0.2 C, 284 mA h (g-Te)−1 at 0.5 C, 260 mA h (g-Te)−1 at 1 C, 230 mA h (g-Te)−1 at 2 C, respectively. When switch-ing to higher C-rate (e.g., 0.2–0.5 C), transitional behavior was observed. The discharge capacity was almost similar to the charge capacity at the lower C-rate, on the other hand, the charge capacity was decreased, causing higher Coulombic efficiency than 100%. This indicates that Na insertion kinetics can be larger than extraction kinetics.

The cell also showed the stable charge/discharge capacity at 1  C-rate over 500  cycles (Fig. S6). After 500 cycles of charge/discharge test, a stable capacity of 330 mA h (g-Te)−1 was obtained with high Coulombic effi-ciency of ca. 100%, suggesting highly reversible sodiation.

After charge/discharge test, the morphology and com-position of the electrode were observed using SEM/EDX (see Fig. 5a, b). The particle morphology of the compos-ite Te@CMK-3 electrode was preserved and the structure of CMK-3 matrix was intact. Te and Na remained evenly distributed except for some scattered Te crystals over the electrode. Hence, we conclude that the Te@CMK-3 com-posite electrode maintained its structure after 50 cycles of charge/discharge test. Since the scattered Te crystal, seen in the back-scattered electron image (see Fig. 5c), did not contain any Na, this crystal appeared to have remained electrochemically inactive or inaccessible during charge/discharge cycling. The presence of such inactive Te crys-tals is the likely cause of the deviation between theoretical and experimental specific capacity; thus, there is much room and potential for further capacity improvements by optimizing the synthetic condition of Te@CMK-3 composite.

Fig. 4 a Charge/discharge curves and b cycling proper-ties for a Na/1 M NaClO4 in EC + PC/Te@CMK-3 three-electrode cell at 0.2 C, 0.5 C, 1 C, and 2 C (cut-off voltages: + 0.7 VNa+/Na and + 3.0 VNa+/Na) after the formation process (10 cycles of charge/discharge cycling)

Journal of Applied Electrochemistry

1 3

4 Conclusion

We have presented an exploratory study of a novel Te@CMK-3 composite electrode for Na-ion rechargeable bat-teries with a favorable specific capacity, rate capability, and stability. The infiltration of Te into CMK-3 composite was confirmed using SEM/TEM imaging, powder XRD, BET analysis, and ICP-AES. The cell showed the stable capacity of 310 mA h  (g-Te)−1 at 0.2 C with the cou-lombic efficiency of ~ 100%, showing highly reversible sodiation. Charge/discharge curves using the ether-based electrolyte revealed the series of unstable intermediates such as sodium polytellurides. They are stable in the car-bonate-based electrolyte, enabling the gradual transition between Te and Na2Te. The Na/Te@CMK-3 cell using the carbonate-based electrolyte showed good rate capability (230 mA h (g-Te)−1 at 2 C) and cyclability (> 500 cycles at 1 C) after initial formation process. This study supports the concept of Te confined in mesoporous carbon electrode as a new class of high-performance chalcogen-based elec-trode for Na-ion rechargeable batteries.

Acknowledgements We thank Benjamin Paul for help with SEM. Partial financial support from the Federal Ministry of Education and Research through funding within the “Sino German TU9 network for electromobility” under the grant reference number 16N11929 is grate-fully acknowledged.

References

1. Kularatna N (2014) Energy storage devices for electronic sys-tems: rechargeable batteries and supercapacitors. Elsevier Sci-ence, New York

2. Dunn B, Kamath H, Tarascon JM (2011) Electrical energy stor-age for the grid: a battery of choices. Science 334(6058):928–935. https ://doi.org/10.1126/scien ce.12127 41

3. Gröger O, Gasteiger HA, Suchsland J-P (2015) Review—electromobility: batteries or fuel cells? J Electrochem Soc 162(14):A2605–A2622. https ://doi.org/10.1149/2.02115 14jes

4. Kushnir D, Sandén BA (2012) The time dimension and lith-ium resource constraints for electric vehicles. Resour Policy 37(1):93–103. https ://doi.org/10.1016/j.resou rpol.2011.11.003

5. Kim SW, Seo DH, Ma XH, Ceder G, Kang K (2012) Elec-trode materials for rechargeable sodium-ion batteries: potential alternatives to current lithium-ion batteries. Adv Energy Mater 2(7):710–721. https ://doi.org/10.1002/aenm.20120 0026

6. Yabuuchi N, Kubota K, Dahbi M, Komaba S (2014) Research development on sodium-ion batteries. Chem Rev 114(23):11636–11682. https ://doi.org/10.1021/cr500 192f

7. Ellis BL, Nazar LF (2012) Sodium and sodium-ion energy stor-age batteries. Curr Opin Solid State Mater Sci 16(4):168–177. https ://doi.org/10.1016/j.cossm s.2012.04.002

8. Xiang X, Zhang K, Chen J (2015) Recent advances and pros-pects of cathode materials for sodium-ion batteries. Adv Mater 27(36):5343–5364. https ://doi.org/10.1002/adma.20150 1527

9. Barpanda P, Oyama G, Nishimura S, Chung SC, Yamada A (2014) A 3.8-V earth-abundant sodium battery electrode. Nat Commun 5:4358. https ://doi.org/10.1038/ncomm s5358

Fig. 5 a Low-magnification SEM image of sodiated Te@CMK-3 electrode after 50 cycles of charge/discharge pro-cess and b high-magnification image where CMK-3 structure is visible, and c its back-scat-tered electron image, and EDX mappings of d C, e Te, and f Na

Journal of Applied Electrochemistry

1 3

10. Dahbi M, Yabuuchi N, Kubota K, Tokiwa K, Komaba S (2014) Negative electrodes for Na-ion batteries. Phys Chem Chem Phys 16(29):15007–15028. https ://doi.org/10.1039/c4cp0 0826j

11. Doeff MM (1993) Electrochemical insertion of sodium into carbon. J Electrochem Soc 140(12):L169. https ://doi.org/10.1149/1.22211 53

12. Komaba S, Murata W, Ishikawa T, Yabuuchi N, Ozeki T, Nakay-ama T, Ogata A, Gotoh K, Fujiwara K (2011) Electrochemical Na insertion and solid electrolyte interphase for hard-carbon electrodes and application to Na-ion batteries. Adv Funct Mater 21(20):3859–3867. https ://doi.org/10.1002/adfm.20110 0854

13. Bai Y, Wang Z, Wu C, Xu R, Wu F, Liu YC, Li H, Li Y, Lu J, Amine K (2015) Hard carbon originated from polyvinyl chlo-ride nanofibers as high-performance anode material for Na-ion battery. ACS Appl Mater Interfaces 7(9):5598–5604. https ://doi.org/10.1021/acsam i.5b008 61

14. Komaba S, Ishikawa T, Yabuuchi N, Murata W, Ito A, Ohsawa Y (2011) Fluorinated ethylene carbonate as electrolyte addi-tive for rechargeable Na batteries. ACS Appl Mater Interfaces 3(11):4165–4168. https ://doi.org/10.1021/am200 973k

15. Bruce PG, Freunberger SA, Hardwick LJ, Tarascon J-M (2012) Li-O2 and Li-S batteries with high energy storage. Nat Mater 11(1):19–29. https ://doi.org/10.1038/nmat3 191

16. Yang Y, Zheng G, Cui Y (2013) Nanostructured sulfur cathodes. Chem Soc Rev 42(7):3018–3032. https ://doi.org/10.1039/C2CS3 5256G

17. Wang C, Wan W, Chen J-T, Zhou H-H, Zhang X-X, Yuan L-X, Huang Y-H (2013) Dual core-shell structured sulfur cathode com-posite synthesized by a one-pot route for lithium sulfur batteries. J Mater Chem A 1(5):1716–1723. https ://doi.org/10.1039/C2TA0 0915C

18. Wei S, Xu S, Agrawral A, Choudhury S, Lu Y, Tu Z, Ma L, Archer LA (2016) A stable room-temperature sodium-sulfur battery. Nat Commun 7:11722. https ://doi.org/10.1038/ncomm s1172 2

19. Xin S, Yin YX, Guo YG, Wan LJ (2014) A high-energy room-temperature sodium-sulfur battery. Adv Mater 26(8):1261–1265. https ://doi.org/10.1002/adma.20130 4126

20. Wu C, Yuan L, Li Z, Yi Z, Li Y, Zeng R, Zhang W, Huang Y (2015) Novel double-cathode configuration to improve the cycling stability of lithium-sulfur battery. RSC Adv 5(19):14196–14201. https ://doi.org/10.1039/C4RA1 5328F

21. Manthiram A, Fu Y, Su YS (2013) Challenges and prospects of lithium-sulfur batteries. Acc Chem Res 46(5):1125–1134. https ://doi.org/10.1021/ar300 179v

22. Abouimrane A, Dambournet D, Chapman KW, Chupas PJ, Weng W, Amine K (2012) A new class of lithium and sodium recharge-able batteries based on selenium and selenium-sulfur as a posi-tive electrode. J Am Chem Soc 134(10):4505–4508. https ://doi.org/10.1021/ja211 766q

23. Luo C, Xu Y, Zhu Y, Liu Y, Zheng S, Liu Y, Langrock A, Wang C (2013) Selenium@mesoporous carbon composite with superior lithium and sodium storage capacity. ACS nano 7(9):8003–8010. https ://doi.org/10.1021/nn403 108w

24. Cotton FA, Wilkinson G, Murillo CA, Bochmann M (1999) Advanced inorganic chemistry, 6th edn. Wiley, New York

25. Koketsu T, Paul B, Wu C, Kraehnert R, Huang Y, Strasser P (2016) A lithium–tellurium rechargeable battery with exceptional

cycling stability. J Appl Electrochem 46(6):627–633. https ://doi.org/10.1007/s1080 0-016-0959-8

26. Seo JU, Seong GK, Park CM (2015) Te/C nanocomposites for Li-Te secondary batteries. Sci Rep 5:7969. https ://doi.org/10.1038/srep0 7969

27. Ding N, Chen S-F, Geng D-S, Chien S-W, An T, Hor TSA, Liu Z-L, Yu S-H, Zong Y (2015) Tellurium@ ordered macroporous carbon composite and free-standing tellurium nanowire mat as cathode materials for rechargeable lithium–tellurium batter-ies. Adv Energy Mater 5(8):1401999. https ://doi.org/10.1002/aenm.20140 1999

28. Zhang J, Yin YX, You Y, Yan Y, Guo YG (2014) A High-capac-ity tellurium@ carbon anode material for lithium-ion batter-ies. Energy Technol 2(9–10):757–762. https ://doi.org/10.1002/ente.20140 2069

29. Zhang J, Yin YX, Guo YG (2015) High-capacity Te anode confined in microporous carbon for long-life Na-ion batteries. ACS Appl Mater Interfaces 7(50):27838–27844. https ://doi.org/10.1021/acsam i.5b091 81

30. Yu CZ, Fan J, Tian BZ, Zhao DY (2004) Morphology devel-opment of mesoporous materials: a colloidal phase separation mechanism. Chem Mater 16(5):889–898. https ://doi.org/10.1021/cm035 011g

31. Zhou HS, Zhu SM, Hibino M, Honma I, Ichihara M (2003) Lith-ium storage in ordered mesoporous carbon (CMK-3) with high reversible specific energy capacity and good cycling performance. Adv Mater 15(24):2107. https ://doi.org/10.1002/adma.20030 6125

32. Joo SH, Choi SJ, Oh I, Kwak J, Liu Z, Terasaki O, Ryoo R (2001) Ordered nanoporous arrays of carbon supporting high dispersions of platinum nanoparticles. Nature 412(6843):169–172. https ://doi.org/10.1038/35084 046

33. Yang CP, Xin S, Yin YX, Ye H, Zhang J, Guo YG (2013) An advanced selenium-carbon cathode for rechargeable lithium-sele-nium batteries. Angew Chem Int Ed 52(32):8363–8367. https ://doi.org/10.1002/anie.20130 3147

34. Kovalenko I, Zdyrko B, Magasinski A, Hertzberg B, Milicev Z, Burtovyy R, Luzinov I, Yushin G (2011) A major constituent of brown algae for use in high-capacity Li-ion batteries. Science 334(6052):75–79. https ://doi.org/10.1126/scien ce.12091 50

35. Ji X, Lee KT, Nazar LF (2009) A highly ordered nanostructured carbon-sulphur cathode for lithium-sulphur batteries. Nat Mater 8(6):500–506. https ://doi.org/10.1038/NMAT2 460

36. Jun S, Joo SH, Ryoo R, Kruk M, Jaroniec M, Liu Z, Ohsuna T, Terasaki O (2000) Synthesis of new, nanoporous carbon with hex-agonally ordered mesostructure. J Am Chem Soc 122(43):10712–10713. https ://doi.org/10.1021/Ja002 261e

37. Adenis C, Langer V, Lindqvist O (1989) Reinvestigation of the structure of tellurium. Acta Crystallogr C 45(6):941–942. https ://doi.org/10.1107/s0108 27018 80144 53

38. Qu Q, Yun J, Wan Z, Zheng H, Gao T, Shen M, Shao J, Zheng H (2014) MOF-derived microporous carbon as a better choice for Na-ion batteries than mesoporous CMK-3. RSC Adv 4(110):64692–64697. https ://doi.org/10.1039/c4ra1 1009a

39. Tang K, Fu L, White RJ, Yu L, Titirici M-M, Antonietti M, Maier J (2012) Hollow carbon nanospheres with superior rate capabil-ity for sodium-based batteries. Adv Energy Mater 2(7):873–877. https ://doi.org/10.1002/aenm.20110 0691