Electronic Supplementary Material (ESI) for RSC Advances. This journal is © The Royal Society of Chemistry 2015 Supplementary Information Facile Synthesis of P2-Type Na0.4Mn0.54Co0.46O2 as High Capacity Cathode Material for Sodium-Ion Batteries Xijun Xu,a Shaomin Ji*,a Ruibo Gao,b Jun Liu*,a aKey Laboratory of Low Dimensional Materials & Application Technology, Ministry of Education, School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China E-mail: [email protected]; [email protected] bJinzhou Petrochemical Co., LTD (JZPC), No. 2, Chongqin Road, Guta district, Jinzhou city, 121001, Liaoning Province, China Table S1. The XRD peak list of P2-type Na0.4Mn0.54Co0.46O2 nanosheets. No. 2-theta(deg) d(ang.) Height(cps) FWHM(deg) Size(ang.) 1 15.692(4) 5.6426(13) 11339(307) 0.198(5) 424(11) 2 31.787(14) 2.8127(12) 1011(92) 0.33(2) 262(17) 3 32.23(2) 2.775(2) 398(58) 0.28(3) 308(32) 4 33.42(5) 2.679(4) 133(33) 0.27(4) 323(45) 5 36.622(10) 2.4518(6) 2618(148) 0.146(9) 599(38) 6 37.79(7) 2.379(4) 115(31) 0.60(9) 145(23) 7 40.169(6) 2.2430(3) 3720(176) 0.220(6) 402(10) 8 44.214(17) 2.0468(8) 1094(95) 0.305(12) 294(12) 9 49.308(9) 1.8466(3) 2236(137) 0.428(6) 213(3) 10 62.310(13) 1.4889(3) 677(75) 0.671(15) 144(3) 11 66.013(14) 1.4140(3) 1474(111) 0.194(16) 510(41) 12 68.364(7) 1.37104(12) 1113(96) 0.163(9) 615(33) 13 75.30(4) 1.2610(6) 225(43) 0.41(4) 257(22) 14 78.20(3) 1.2214(4) 185(39) 0.81(5) 131(7) 15 80.186(12) 1.19603(14) 388(57) 0.187(16) 580(50) 16 82.94(3) 1.1632(3) 109(30) 0.13(4) 873(267) 17 86.809(18) 1.12099(18) 386(57) 0.28(3) 407(38) To better understand the structure information of the layered Na0.4Mn0.54Co0.46O2, lattice constants of a=2.831 Å and c=11.286 Å were calculated by formula (1). 2 2 2 2 2 -1/2 d(hkl) = [4(h +hk+k )/3a +l /c ] (1) ) . u . a Precursor ( y t i s n ) 2 e 2 t JCPDS No.01-1061 2 ) ( ) 0 n 2 ) 4 2 1 I 4 6 1 ) ( ) ( 2 0 ) 1 ( 0 2 3 4 3 4 ( ( 3 ( 20 40 60 80 2-Theta(degree) Figure S1. Typical XRD patterns of the Mn2O3 precursor and JCPDS No.01-1061. Element Weight% Atom% O K 28.80 55.30 NaK 07.70 10.40 MnK 33.90 18.90 CoK 29.60 15.40 Figure S2. The EDS spectrum of the final P2-type Na0.4Mn0.54Co0.46O2 nanosheets. Firstly, with the EDS data, we can calculate the proportion of cobalt and manganese. Then combined with the initial and second charge capacities, the sodium content in the sample was also calculate. With this route, this oxide cathode we finally got was Na0.4Mn0.54Co0.46O2. Element Weight% Atom% O K 18.00 41.90 NaK 04.90 07.90 MnK 30.00 20.30 CoK 47.20 29.80 Figure S3. The EDS spectrum of P2-Na0.4Co0.6Mn0.4O2 cathode. (a) (b) Na0.4Mn0.4Co0.6O2 4 ) Na Mn Co O 2 0.4 0.54 0.46 2 0 0 ( ) ) ) A . 2 1 ) u 2 ) m . 0 4 ( ) 0 ) ( ) a ) 0 ) 3 0 ( t 4 0 6 1 2 0 1 y 0 ( 1 n 0 ( 1 t 1 0 1 1 i ( e 1 ( ( ( r ( s r n 0 u e t C n I 1st cycle -2 2nd cycle 3rd cycle 20 40 60 80 1.5 2.0 2.5 3.0 3.5 4.0 4.5 2 (degree) Voltage (V) vs. Na+/Na (d) 300 (c) 100 4.0 250 80 3.5 ) ) g / ) 200 % h ( V ( 1st A 3.0 60 y e c m 2nd ( n g 150 Unit: mA/g 10 10 e a y i 10th t 20 t c l i 2.5 40 i c 20 f o 70th 100 50 f a V E p a 100 2.0 Charge C 20 50 Discharge 200 1.5 Efficiency 0 0 0 40 80 120 160 0 20 40 60 80 Capacity(mAh/g) Cycle number Figure S4. The typical XRD patterns (a) and electrochemical performance (b-d) of P2-Na0.4Co0.6Mn0.4O2 cathode: (a) the XRD patterns of Na0.4Co0.46Mn0.54O2 and Na0.4Co0.6Mn0.4O2; (b) the first three CV curves of Na0.4Co0.6Mn0.4O2; (c) the capacity-voltage curve of Na0.4Co0.6Mn0.4O2; (d) the rate capability of Na0.4Co0.6Mn0.4O2. .