Supporting Information. Amorphous Red Phosphorus Embedded in Highly Ordered. Mesoporous Carbon with Superior Lithium and Sodium Storage.

Transcription

1 Supporting Information Amorphous Red Phosphorus Embedded in Highly Ordered Mesoporous Carbon with Superior Lithium and Sodium Storage Capacity Weihan Li, Zhenzhong Yang, Minsi Li, Yu Jiang, Xiang Wei, Xiongwu Zhong, Lin Gu, ǁ, Yan Yu,,,* Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui , China Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin , China State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui, , China Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing , China ǁ Collaborative Innovation Center of Quantum Metter, Beijing , P. R. China *Corresponding Author: Yan Yu, Tel.: address:

2 Experimental Sections Preparation method: Similar to our previous work 1, 0.3 g commercial red P (purity 99%, Sinopharm Chemical Reagent Co., Ltd.) and g CMK-3 (Nanjing XFNANO Materials Tech Co., Ltd, China) were separately placed in one sealed steel vessel. The sealed vessel was filled with argon as protection gas and then heated to 450 C and held at the temperature for 3h, where heating rate is 4 Cmin -1. After cooling to 260 C, the vessel was held at this temperature for 24h to convert white P to red P, where cooling rate is 1 Cmin -1. After the sealed vessel naturally cooled to room temperature, the chemically stable P@CMK-3 was obtained by washing with CS 2 (purity 99%, Sinopharm Chemical Reagent Co., Ltd.) to remove the white P generated during the condensation process and drying under vacuum. We then used 0.75 g commercial red P and g CMK-3 with the same process to prepare the P@CMK-3 composite with higher P weight content (~60 wt%). Characterization: X-ray diffraction (XRD) (TTR-, Rigaku, Japan) using Cu Kα radiation was applied to characterize the crystal structure of materials. Fourier transform infrared (FTIR) spectra were performed by a Thermo Nicolet 8700 FTIR spectrophotometer. Raman scattering spectra were recorded with a Renishaw System 2000 spectrometer. Field-Emission Scanning electron microscopy (FESEM) investigations were performed using a JSM-6700 field-emission scanning electron microscope (JEOL, Tokyo, Japan) operated at 5 kev. A JEOL 4000EX transmission electron microscope (HRTEM) (JEOL, Tokyo, Japan) was used to study the structure and elemental mapping of materials. Nitrogen adsorption/desorption isotherms were measured with an ASAP 2020 Accelerated Surface Area and Porosimetry instrument. Electrochemical Characterization: The P@CMK-3 composite (80 wt%) was mixed with acetylene black (10 wt%) and poly(vinylidene fluoride) binder (10 wt%) to make a homogeneous slurry. Then the slurry was casted onto copper foil using a doctor blade, followed by drying in a vacuum oven over night at 60 ºC. The mass loading of

3 the electrodes is about 1~1.3 mg/cm 2. Electrochemical test cells (2032 coin cells) for lithium-ion batteries were assembled with lithium foil as counter and reference electrodes, 1 M LiPF 6 in a mixture of EC and DEC (1:1 = v : v) as electrolyte, and Celgard 2400 membrane as a separator. Electrochemical test cells (2032 coin cells) for sodium-ion batteries were assembled with sodium foil as counter and reference electrodes, 1 M NaClO 4 in a mixture of EC and DMC (1:1 = v : v) as electrolyte, and glass fiber (GF/D) from Whatman as a separator. The cells were assembled in an argon-filled glovebox. The galvanostatic charge-discharge tests for lithium-ion and sodium-ion batteries were conducted between to 2.5 V and to 2.0 V, respectively. For the rate performance, the C-rate is calculated by the following equation as: C-rate = C (1C=2595 ma/g phosphorus, 819 ma/g composite ). To calculate the specific capacity contribution of phosphorus in the electrodes, a formula can be carried out as: Specific capacity based on where the capacity contribution of CMK-3 in the composite is calculated by the following equation as: Capacity contribtuion of CMK 3 = Capacity of CMK 3 Weight percentage of CMK 3. 3,4

4 Figure S1 (A) N 2 sorption/desorption isotherm and (B) pore size distribution curves of CMK-3 and P@CMK-3. The Brunauer-Emmett-Teller (BET) specific surface of CMK-3 and P@CMK-3 investigated here as and m 2 g -1, respectively. The pore size distributions were investigated by the Barrett-Joyner-Halenda (BJH) method. The pore volume of CMK-3 and P@CMK-3 investigated here as 1.41 and cm 3 g -1. Figure S2 High angle annular dark-field STEM (HAADF-STEM) image (A) and corresponding carbon (B) and phosphorus (C) elemental mapping of one area marked by the black square of P@CMK-3. Figure S3 Thermogravimetric analysis (TGA) of the P@CMK-3. The content of P in the P@CMK-3 calculated from the TGA is ca wt%. (Note: red P was totally vaporized into N 2 flow). This analysis was taken in N 2 atmosphere with a heating rate of 10 C min -1.

5 Figure S4 Voltage profiles of CMK-3 electrodes for (A) LIBs cycled between 0.001V and 2.5 V vs. Li + /Li at a cycling rate of 0.25 C and (B) NIBs cycled between 0.001V and 2.0 V vs. Na + /Na at a cycling rate of 0.2 C; Electrochemical performance of CMK-3 electrodes for LIBs and NIBs cycled between V and 2.5 V vs. Li + /Li and and 2.0 V vs. Na + /Na, respectively. Capacity-cycle number curves of CMK-3 electrodes at a cycling rate of 0.25 C for LIBs (C) and 0.2 C for NIBs (D). Figure S5 Electrochemical performance of P@CMK-3 composite with a mass loading of 2.2 mg/cm 2 for LIBs and NIBs cycled between V and 2.5 V vs. Li + /Li and and 2.0 V vs. Na + /Na. Capacity-cycle number curves of P@CMK-3 electrode at a cycling rate of 0.25 C for LIBs (A) and 0.2 C for NIBs (B)

6 Figure S6 (A) Thermogravimetric analysis (TGA) of the with higher phosphorus content. The content of P in the P@CMK-3 calculated from the TGA is ca. ~60 wt%. (Note: red P was totally vaporized into N 2 flow). This analysis was taken in N 2 atmosphere with a heating rate of 10 C min -1. (B) Electrochemical performance of P@CMK-3 composite with a phosphorus content of ~60 wt% for LIBs and NIBs cycled between V and 2.5 V vs. Li + /Li. The capacities are calculated based on the mass of the P@CMK-3 composites. Table S1 Comparison of electrochemical performance between P@CMK-3 (the current work with higher P content) and other previous works about carbon/p composites as anode materials in LIBs. The current densities and capacities are calculated based on the mass of the composites. P content (wt%) Current density (ma/g) Cycle performance capacity/cycling times P@CMK-3 ~60 wt% 200 ma/g 1440 mahg -1 /50 cycles (the current work) Ball milled P/Carbon 70 wt% 100 ma/g ~700 mahg -1 /50 cycles (Ref. 15) PCNFs/P (Ref. 16) 34.4 wt% 100 ma/g ~917 mahg -1 /50 cycles rgo-bp (Ref. 17) ~46 wt% 230 ma/g ~970 mahg -1 /50 cycles Black P-carbon (Ref. 19) ~70 wt% 100 ma/g ~600 mahg -1 /50 cycles rgo/p (Ref. 22) ~70 wt% 100 ma/g 1173 mahg -1 /50 cycles Activated carbon/p (Ref. ~70 wt% 260 ma/g 900 mahg -1 /20 cycles 23) Porous carbon/p (Ref. 28) 30.5 wt% 100 ma/g 745 mahg -1 /55 cycles

7 Table S2 Specific capacity of lithium storage for CMK-3 and red P. C-rate (C) capacity CMK-3 capacity Red P capacity Table S3 Specific capacity of sodium storage for P@CMK-3, CMK-3 and red P. C-rate (C) P@CMK-3 capacity CMK-3 capacity Red P capacity Figure S7 Excellent cycle performance of P@CMK-3 electrodes for LIBs at 1.2 and 5 C (A) and NIBs at 1 and 5C (B) with activation firstly at low current density. The capacities here are calculated based on the total mass of the composite.

8 Figure S8 TEM and HRTEM images of the at the lithiation state (A&B) and the sodiation state (C&D). The areas marked black ovals in C and D correspond to Li 3 P and Na 3 P nanoparticles. Figure S9 High angle annular dark-field STEM (HAADF-STEM) image (A) and corresponding carbon (B) and phosphorus (C) elemental mapping of P@CMK-3 at the lithiation state; (D) line profile across A, B and C that show the relative intensities of the HAADF-STEM image and the two elements.

9 Figure S10 SEM image of commercial red P particles. Figure S11 Nyquist plots of the P@CMK-3 electrodes in LIBs (A) and NIBs (B) after 10, 20 and 30 cycles. The electrodes were controlled to be fully charge states. For LIBs and NIBs cycled at 0.25 and 0.2 C, respectively, the Nyquist plots after 10, 20 and 30 cycles remain almost the same, indicating that the SEI is table. SEM images of the P@CMK-3 electrodes in LIBs (C) after 85 cycles and NIBs (D) after 60 cycles. (The current densities in LIBs and NIBs are 0.25 and 0.2 C, respectively)

10 Figure S12 Rate performance of pure CMK-3 in LIBs (A) and NIBs (B) (0.6 ~ 12 C for LIBs and 0.6 ~9.8 C for NIBs). Cycle performance of CMK-3 electrodes for LIBs at 1.2 and 5 C (C) and NIBs at 1 and 5 C (D) with activation firstly at low current density. References: 1. Li, W.; Yang, Z.; Jiang, Y.; Yu, Z.; Gu, L.; Yu, Y. Carbon 2014, 78, Zhu, Y.; Han X.; Xu Y.; Liu, Y.; Zheng S.; Xu K.; Hu L.; Wang C. ACS Nano, 2013, 7, Wu, L.; Hu, X.; Qian J.; Pei, F.; Wu, F.; Mao, R.; Ai, X.; Yang, H.; Cao, Y.; Energy Environ. Sci. 2014, 7, Wang, L.; He, X.; Li, J.; Sun, W.; Gao, J.; Guo, J.; Jiang, C. Angew. Chem., Int. Ed. 2012, 51,