All-Solid-State Lithium Organic Battery with Composite Polymer Electrolyte and Pillar[5]quinone Cathode

Transcription

1 All-Solid-State Lithium rganic Battery with Composite Polymer Electrolyte and Pillar[5]quinone Cathode Zhiqiang Zhu, Meiling Hong, Dongsheng Guo, Jifu Shi, Zhanliang Tao, Jun Chen, * Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) and State Key Laboratory of Elemento rganic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering, College of Chemistry, Nankai University, Tianjin ; Key Laboratory of Renewable Energy & Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou , China. Corresponding Author chenabc@nankai.edu.cn (J. C.) Preparation of the composite polymer electrolytes. All reagents used were of analytical grade. Si 2 nanoparticles with the size of 7-10 nm and Ti 2 powder (P25) were supplied by Degussa AG of Germany. The all-solid-state electrolyte was prepared through the following. First, different amounts of Si 2 or Ti 2 (0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.07, 0.1 g) was added into 1 ml of 0.6 M LiCl 4 in ethanol. After full dissolution of the nanoparticles by ultrasonication, 1 g PMA/PEG hybrid (weight ratio of 65:35), which was prepared according to our previous reports, 1 was added into the solution and kept ultrasonication for 1h. Then, the mixture was placed over night to make the uniform distribution of LiCl 4 in the polymer electrolyte. Finally, the all-solid-state composite polymer electrolyte (CPE) was obtained by volatilizing ethanol at 80 o C. The ionic conductivity of the as-prepared CPE was measured with a Parstat 2273 potentiostat/galvanostat analyzer (Princeton Applied Research & AMETEK Company) over a frequency range of 10 Hz 100 khz at various temperatures. S1

2 General synthetic routes to the target produce pillar[5]quinone. Me Me Me (CH 2 ) n BF 3 (C 2 H 5 ) 2 Me Me Me Me Me Me Me (NH 4 ) 2 [Ce(N 3 ) 6 ] Me Me 1,4-dimethoxypillar[5]arene pillar[5]quinone Scheme S1. General synthetic routes to the target produce pillar[5]quinone. 1,4-Dimethoxypillar[5]arene 2 A solution of p-dimethoxybenzene (13.8 g, mmol) in 1,2-dichloroethane (180 ml) was stirred under argon at 20 o C for 30 min. Then, boron trifluoride diethyl etherate (BF 3 (C 2 H 5 ) 2, 12.5 ml, mmol) was added to the solution and the mixture was stirred for 15 minutes. The reaction mixture was poured into methanol and the resulting precipitate was collected by filtration. The obtained solid was re-crystallized from acetonitrile to yield 3.8 g of 1,4-dimethoxy pillar[5]arene as a while solid. Yield: 25.3%. 1 H NMR (CDCl 3 ) 6.82 (CH=C-, s, 10H), 3.82 (CH 2 -, s, 10H), 3.70 (CH 3 -, s, 30H). MALDI-TF HR-MS (m/z): calcd. for C 45 H [M] + : ; Found: [M] + : Pillar[5]quinone 3 A solution of 1,4-dimethoxypillar[5]arene (1.0 g, 1.3 mmol) in dichloromethane (60 ml) and water (10 ml) was stirred under argon at room temperature. Then, ceric ammonium nitrate ((NH 4 ) 2 [Ce(N 3 ) 6 ], 8.0 g, 14.7 mmol) was added. The reaction mixture was stirred for 30 min to give a yellow suspension. After filtration, the resulting precipitate was washed with water and then ethyl alcohol. Column chromatography (silica gel, 100% dichloromethane) afforded 0.46 g of pale yellow powders. Yield: 60.2%. 1 H NMR (CDCl 3 ) 3.50 (CH 2 -, s, 10H), 6.77 (CH=C-, s, S2

3 10H). MALDI-TF HR-MS (m/z): calcd. for C 35 H [M] + : ; Found: [M+H] + : Electrochemical Measurements. Electrode properties were evaluated using CR2032 coin-type cells assembled in an argon-filled glove box (Mikrouna Universal 2440/750). For liquid cell, the cathode was composed of pillar[5]quinone (P5Q) (65 wt%), porous carbon black spheres (PCBS, 40 nm, 320 m 2 g -1, 0.36 Ω cm, 25 wt%), single-walled carbon nanotubes (SWCN, 3 wt%), graphene (G, 2 wt%), and polyvinylidene fluoride (PVdF) (5 wt%). 1 The electrolyte was 1 M LiPF 6 solution in a mixed solvent of ethylene carbonate (EC) and dimethyl carbonate (DMC) (1:1 in volume). Celgard 2300 porous membrane was used as separator. For solid cell, the prepared PMA/PEG-LiCl 4-3 wt% Si 2 composite polymer electrolyte (CPE) was introduced into the cathode as lithium conductor. P5Q (55 wt%), PCBS (25 wt%), SWCN (3 wt%), G (2 wt%), CPE (10 wt%), and PVdF (5 wt%) were mixed in a mixed solvent of acetonitrile (AN) and N-methyl pyrrolidine (NMP) and then cast on to aluminum sheets. Another cathode composition of P5Q- -PCBS-SWCN-G-CPE-PVdF with 70:10:3:2:10:5 was also tested. Typical thickness of the cathode films was about 20 µm with a packing density of about 0.8 g cm 3. The PMA/PEG-LiCl 4-3 wt% Si 2 CPE membranes prepared by a hot-pressing technique were used as electrolyte and separator. The CPE membranes had an average thickness of 50 µm. The thickness of the electrode and CPE films were measured using a micrometer and further confirmed by SEM analysis (Figure S3). The charge-discharge experiments were performed on a LAND battery testing system at room temperature. Figure S1. SEM images of the used (a) Ti 2 and (b) Si 2. S3

4 Figure S2. SEM images of (a) synthsized pillar[5]quinone and (b) the prepared electrode. Figure S3. SEM image of the cathode and CPE films. Figure S4. The initial discharge-charge curves of pillar[5]quinone in 1 M LiPF 6 EC:DMC (1:1 S4

5 in volume). Figure S5. Cycle performance of the all-soild-state battery with cathode containing 70 wt% P5Q. Gravimetric Energy density Calculations The specific energy density (E, considering the electrode materials only) of different tpyes of batteries is calculated using the following equation: E = C C c c C + C a a ( Vc Va) where C is the specific capacity of the electrode (i.e. including the additives in the electrode), and V is the average opertaion volatge (vs. Li + /Li) of the electrode. The subscipts c and a represent cathode and anode, respectively. Table S1 demonstrates the values used for calculations for several common liquid inorgaic lithium-transition-metal-oxides/graphite systems and all-solid-state lithium organic battery proposed in this work. The estimated energy density of each type of battery is also presented. S5

6 Table S1. Values used for calculating epecific energy for several lithium battery systems and estimated energy densities of these systems. Cathode/Anode Cathode capacity (mah/g) Active content material in cathode (wt %) Anode capacity (mah/g) Active material content in anode (wt %) Voltage difference (V) Specific Energy (Wh/kg) Estimated energy density of the battery (Wh/kg) LiCo 2 /Graphite LiFeP 4 /Graphite LiMn 2 4 /Graphite Li/P5Q (55 wt%) Li P5Q (70 wt%) For LiCo 2 /graphite, LiFeP 4 /graphite, and LiMn 2 4 /graphite systems, the theoretical values of the cathode capacity, anode capacity, and voltage difference are used to calculate the specific energy, which means that the practical value should be lower. The following references were consulted to obtain these values: LiCo 2, 4 LiFeP 4, 5 LiMn 2 4, 6 graphite 7. The value of the active material content in both cathode and anode for these three systems are assumed to be 90 wt%, which are mostly used in research papers. For Li/P5Q system, two batteries comprising the cathodes with 55 wt% and 70 wt% P5Q are calculated. We use the intial capacity of each battery as the cathode capacity. In addtion, a value of 3800 mah/g was used as the capacity of lithium anode (C theo = 3860 mah/g). Since no binder or conductive additive are needed in lithium anode, the active material content is 100%. For all systems, the energy densities of the batteries are estimated by roughly assuming a one-third reduction factor related to the weight of the whole battery components. 8 Volumetric Energy Density Calculations The thickness of the P5Q cathode was about 20 µm with a packing density of about 0.8 g cm 3. Based on the initial capacities of the cathodes containing 55 wt% P5Q and 70 wt% P5Q, the volumetric energy densities for the two cathodes are ~480 and ~590 Wh/L, respectively. However, because the batteries investigated in this paper are laboratory-scale cells, it can t S6

7 simply use presented electrode (~20 µm) and electrolyte thickness (~50 µm) to evaluate the volumetric energy density of the battery. Instead, we calculate the theoretical volumetric energy density of the proposed solid-state P5Q/lithium battery. For comparison, the value of the LiCo 2 /graphite system is also calculated. Table S2 shows values employed for calculations (density values used: LiCo 2 = 5.0 g cm 3, graphite = 2.1 g cm 3, P5Q = 1.5 g cm 3, Li = 0.59 g cm 3 ). It should be pointed out that for the volumetric energy density can be decreased by factors such as electrode additives and other electrode engineering constraint in a real cell. Nevertheless, this type of solid-state lithium organic battery still holds promise as high energy battery system for next generation lithium batteries due to the abundance of organic materials as well as their high gravimetric energy densities. Table S2. Theoretical volumertic energy density of LiCo 2 /Graphite of Li/P5Q battery systems. Cathode/Anode Cathode Anode capacity capacity mah/g Ah/L mah/g Ah/L Voltage difference (V) Theoretical volumertic energy density (Wh/L) LiCo 2 /Graphite Li/P5Q Supported References: (1) Huang, W.; Zhu, Z.; Wang, L.; Wang, S.; Li, H.; Tao, Z.; Shi, J.; Guan, L.; Chen, J. Angew. Chem. Int. Ed. 2013, 52, (2) goshi, T.; Kanai, S.; Fujinami, S.; Yamagishi, T.-a.; Nakamoto, Y. J. Am. Chem. Soc. 2008, 130, (3) Cao, D.; Kou, Y.; Liang, J.; Chen, Z.; Wang, L.; Meier, H. Angew. Chem. Int. Ed. 2009, 48, (4) Linden. D.; Reddy. T. B. in Handbook of Batteries (3rd Edition) (McGraw-Hill, 2002). (5) Chung. S. Y.; Bloking, J. T.; Chiang. Y. M. Nat. Mater. 2002, 1, S7

8 (6) Cheng, F.; Wang, H.; Zhu, Z.; Wang, Y.; Zhang, T.; Tao, Z.; Chen, J. Energy Environ. Sci. 2011, 4, (7) Dahn, J. R.; Zheng, T.; Liu, Y.; Xue, J. Science 1995, 270, (8) Hassoun, J.; Lee, K. S.; Sun, Y. K.; Scrosati, B. J. Am. Chem. Soc. 2011, 133, S8