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Erschienen in: Journal of Materials Science 13/2018

06.04.2018 | Electronic materials

Improved cycle performance of nitrogen and phosphorus co-doped carbon coatings on lithium nickel cobalt aluminum oxide battery material

verfasst von: Peng Gao, Yunpeng Jiang, Yongming Zhu, Huili Hu

Erschienen in: Journal of Materials Science | Ausgabe 13/2018

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Abstract

Nitrogen–phosphorus co-doped nanoscale carbon coating (N/P–C) was constructed on the surface of LiNi0.8Co0.15Al0.05O2 (NCA). The coated material showed a shell–core structure, the core layer was NCA, the shell layer was N/P–C, and the coating was evenly distributed on the surface of the material. The coating improves electron transport path in the structure of NCA, increases conductivity, protects the electrode material, suppresses dissolution of the metal ions and improves stability. In this experiment, aniline (ani) was used as the carbon source and the nitrogen source, and phytic acid was used as the carbon source and the phosphorus source. They were mixed at a mass ratio of m (NCA)/m (C) = 100:0.5, 100:1.0 and 100:2.0, respectively, and then annealed to form a uniform coating. By comparison, it can be concluded that the coating has the best electrochemical performance when the coating mass fraction is 1.0%. At the current density of 1 C, the capacity retention rate was 90.7% after 200 cycles, higher than uncoated material (70%).

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Literatur
1.
Zurück zum Zitat Armand M, Tarascon JM (2008) Building better batteries. Nature 451:652–657CrossRef Armand M, Tarascon JM (2008) Building better batteries. Nature 451:652–657CrossRef
2.
Zurück zum Zitat Bruce PG, Scrosati B, Tarascon JM (2008) Lithium batteries nanomaterials for rechargeable lithium batteries. Angew Chem Int Ed 47:2930–2946CrossRef Bruce PG, Scrosati B, Tarascon JM (2008) Lithium batteries nanomaterials for rechargeable lithium batteries. Angew Chem Int Ed 47:2930–2946CrossRef
3.
Zurück zum Zitat Goodenough JB, Park KS (2013) The Li-ion rechargeable battery: a perspective. J Am Chem Soc 135:1167–1176CrossRef Goodenough JB, Park KS (2013) The Li-ion rechargeable battery: a perspective. J Am Chem Soc 135:1167–1176CrossRef
4.
Zurück zum Zitat Etacheri V, Marom R, Elazari R, Salitra G, Aurbach D (2011) Challenges in the development of advanced Li-ion batteries: a review. Energy Environ Sci 4:3243–3262CrossRef Etacheri V, Marom R, Elazari R, Salitra G, Aurbach D (2011) Challenges in the development of advanced Li-ion batteries: a review. Energy Environ Sci 4:3243–3262CrossRef
5.
Zurück zum Zitat Hwang S, Chang W, Kim SM et al (2014) Investigation of changes in the surface structure of Li x Ni0.8Co0.15Al0.05O2 cathode materials induced by the initial charge. Chem Mater 26(2):1084–1092CrossRef Hwang S, Chang W, Kim SM et al (2014) Investigation of changes in the surface structure of Li x Ni0.8Co0.15Al0.05O2 cathode materials induced by the initial charge. Chem Mater 26(2):1084–1092CrossRef
6.
Zurück zum Zitat Bak SM, Nam KW, Chang W et al (2013) Correlating structural changes and gas evolution during the thermal decomposition of charged Li x Ni0.8Co0.15Al0.05O2 cathode materials. Chem Mater 25(3):337–351CrossRef Bak SM, Nam KW, Chang W et al (2013) Correlating structural changes and gas evolution during the thermal decomposition of charged Li x Ni0.8Co0.15Al0.05O2 cathode materials. Chem Mater 25(3):337–351CrossRef
7.
Zurück zum Zitat Watanabe S, Kinoshita M, Hosokawa T, Morigaki K, Nakura K (2014) Capacity fade of LiAl y Ni1−x−y–Co x O2 cathode for lithium-ion batteries during accelerated calendar and cycle life tests. J Power Sources 258:210–217CrossRef Watanabe S, Kinoshita M, Hosokawa T, Morigaki K, Nakura K (2014) Capacity fade of LiAl y Ni1−xy–Co x O2 cathode for lithium-ion batteries during accelerated calendar and cycle life tests. J Power Sources 258:210–217CrossRef
8.
Zurück zum Zitat Shim J, Kostecki R, Richardson T, Song X, Striebel KA (2002) Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature. J Power Sources 112:222–230CrossRef Shim J, Kostecki R, Richardson T, Song X, Striebel KA (2002) Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature. J Power Sources 112:222–230CrossRef
9.
Zurück zum Zitat Abraham DP, Twesten RD, Balasubramanian M, Petrov I, McBreen J, Amine K (2002) Surface changes on LiNi0.8Co0.2O2 particles during testing of high-power lithium-ion cells. Electrochem Commun 4:620–625CrossRef Abraham DP, Twesten RD, Balasubramanian M, Petrov I, McBreen J, Amine K (2002) Surface changes on LiNi0.8Co0.2O2 particles during testing of high-power lithium-ion cells. Electrochem Commun 4:620–625CrossRef
10.
Zurück zum Zitat Bak YR, Chung Y, Ju JH, Hwang MJ, Lee Y, Ryu KS (2011) Structure and electrochemical performance of Co0.15Al0.05O2 cathodes before and after treatment with Co3(PO4)2 or AlPO4 by in situ chemical method. J New Mater Electrochem Syst 14:203–207 Bak YR, Chung Y, Ju JH, Hwang MJ, Lee Y, Ryu KS (2011) Structure and electrochemical performance of Co0.15Al0.05O2 cathodes before and after treatment with Co3(PO4)2 or AlPO4 by in situ chemical method. J New Mater Electrochem Syst 14:203–207
11.
Zurück zum Zitat Chung YM, Ryu SH, Ju JH, Bak YR, Hwang MJ, Kim KW, Cho KK, Ryu KS (2010) A surfactant-based method for carbon coating of LiNi0.8Co0.15Al0.05O2 Cathode in Li ion batteries. Bull Korean Chem Soc 31:2304–2308CrossRef Chung YM, Ryu SH, Ju JH, Bak YR, Hwang MJ, Kim KW, Cho KK, Ryu KS (2010) A surfactant-based method for carbon coating of LiNi0.8Co0.15Al0.05O2 Cathode in Li ion batteries. Bull Korean Chem Soc 31:2304–2308CrossRef
12.
Zurück zum Zitat Cho Y, Lee YS, Park SA, Lee Y, Cho J (2010) LiNi0.8Co0.15Al0.05O2 cathode materials prepared by TiO2 nanoparticle coatings on Ni0.8Co0.15Al0.05(OH)2 Precursors. Electrochim Acta 56:333–339CrossRef Cho Y, Lee YS, Park SA, Lee Y, Cho J (2010) LiNi0.8Co0.15Al0.05O2 cathode materials prepared by TiO2 nanoparticle coatings on Ni0.8Co0.15Al0.05(OH)2 Precursors. Electrochim Acta 56:333–339CrossRef
13.
Zurück zum Zitat Cho Y, Cho J (2010) Significant improvement of LiNi0.8Co0.15Al0.05O2 cathodes at 60 °C by SiO2 dry coating for Li-ion batteries. J Electrochem Soc 157:A625–A629CrossRef Cho Y, Cho J (2010) Significant improvement of LiNi0.8Co0.15Al0.05O2 cathodes at 60 °C by SiO2 dry coating for Li-ion batteries. J Electrochem Soc 157:A625–A629CrossRef
14.
Zurück zum Zitat Visbal H, Aihara Y, Ito S, Watanabe T, Park Y, Doo S (2016) The effect of diamond-like carbon coating on LiNi0.8Co0.15Al0.05O2 particles for all solid-state lithium-ion batteries based on Li2S–P2S5 glass–ceramics. J Power Sources 314:85–92CrossRef Visbal H, Aihara Y, Ito S, Watanabe T, Park Y, Doo S (2016) The effect of diamond-like carbon coating on LiNi0.8Co0.15Al0.05O2 particles for all solid-state lithium-ion batteries based on Li2S–P2S5 glass–ceramics. J Power Sources 314:85–92CrossRef
15.
Zurück zum Zitat Xia S, Zhang Y, Dong P, Zhang Y (2014) Improve electrochemical performance of CeO2 surface modification LiNi0.8Co0.15Al0.05O2 cathode material. Eur Phys J Appl Phys 66(3):30403CrossRef Xia S, Zhang Y, Dong P, Zhang Y (2014) Improve electrochemical performance of CeO2 surface modification LiNi0.8Co0.15Al0.05O2 cathode material. Eur Phys J Appl Phys 66(3):30403CrossRef
16.
Zurück zum Zitat Xia SB, Zhang YJ, Dong P, Yang RM, Zhang Y (2014) CeO2 surface modification to improve cycle and storage performance on lithium ion battery cathode material LiNi0.80Co0.15Al0.05O2. Chin J Inorg Chem 30(3):529–535 Xia SB, Zhang YJ, Dong P, Yang RM, Zhang Y (2014) CeO2 surface modification to improve cycle and storage performance on lithium ion battery cathode material LiNi0.80Co0.15Al0.05O2. Chin J Inorg Chem 30(3):529–535
17.
Zurück zum Zitat Huang B, Li X, Wang Z, Guo H, Shen L, Wang J (2014) A comprehensive study on electrochemical performance of Mn-surface-modified LiNi0.8Co0.15Al0.05O2 synthesized by an in situ oxidizing-coating method. J Power Sources 252:200–207CrossRef Huang B, Li X, Wang Z, Guo H, Shen L, Wang J (2014) A comprehensive study on electrochemical performance of Mn-surface-modified LiNi0.8Co0.15Al0.05O2 synthesized by an in situ oxidizing-coating method. J Power Sources 252:200–207CrossRef
18.
Zurück zum Zitat Huang B, Li X, Wang Z, Guo H, He Z, Wang R, Wang J, Xiong X (2014) Enhanced electrochemical performance in LiNi0.8Co0.15Al0.05O2 cathode material: resulting from Mn-surface-modification using a facile oxidizing-coating method. Mater Lett 115:49–52CrossRef Huang B, Li X, Wang Z, Guo H, He Z, Wang R, Wang J, Xiong X (2014) Enhanced electrochemical performance in LiNi0.8Co0.15Al0.05O2 cathode material: resulting from Mn-surface-modification using a facile oxidizing-coating method. Mater Lett 115:49–52CrossRef
19.
Zurück zum Zitat Lee MJ, Noh M, Park MH, Jo M, Kim H, Nam H, Cho J (2015) The role of nanoscale-range vanadium treatment in LiNi0.8Co0.15Al0.05O2 cathode materials for Li-ion batteries at elevated temperatures. J Mater Chem A 3(25):13453–13460CrossRef Lee MJ, Noh M, Park MH, Jo M, Kim H, Nam H, Cho J (2015) The role of nanoscale-range vanadium treatment in LiNi0.8Co0.15Al0.05O2 cathode materials for Li-ion batteries at elevated temperatures. J Mater Chem A 3(25):13453–13460CrossRef
20.
Zurück zum Zitat Myung ST, Izumi K, Komaba S, Yashiro H, Bang HJ, Sun YK, Kumaga N (2007) Functionality of oxide coating for Li[Li0.05Ni0.4Co0.15Mn0.4]O2 as positive electrode materials for lithium-ion secondary batteries. J Phys Chem C 111(10):4061–4067CrossRef Myung ST, Izumi K, Komaba S, Yashiro H, Bang HJ, Sun YK, Kumaga N (2007) Functionality of oxide coating for Li[Li0.05Ni0.4Co0.15Mn0.4]O2 as positive electrode materials for lithium-ion secondary batteries. J Phys Chem C 111(10):4061–4067CrossRef
21.
Zurück zum Zitat Kim HB, Park BC, Myung ST, Amine K, Prakash J, Sun YK (2008) Electrochemical and thermal characterization of AlF3-coated LiNi0.8Co0.15Al0.05O2 cathode in lithium-ion cells. J Power Sources 179(1):347–350CrossRef Kim HB, Park BC, Myung ST, Amine K, Prakash J, Sun YK (2008) Electrochemical and thermal characterization of AlF3-coated LiNi0.8Co0.15Al0.05O2 cathode in lithium-ion cells. J Power Sources 179(1):347–350CrossRef
22.
Zurück zum Zitat Park B, Kim H, Bang H (2008) Improvement of electrochemical performance of Li[Ni0.8Co0.15Al0.05]O2 cathode materials by AlF3 coating at various temperatures. Ind Eng Chem Res 47(11):3876–3882CrossRef Park B, Kim H, Bang H (2008) Improvement of electrochemical performance of Li[Ni0.8Co0.15Al0.05]O2 cathode materials by AlF3 coating at various temperatures. Ind Eng Chem Res 47(11):3876–3882CrossRef
23.
Zurück zum Zitat Lee SH, Yoon CS, Amine K, Sun YK (2013) Improvement of long-term cycle performance of Li[Ni0.8Co0.15Al0.05]O2 by AlF3 coating. J Power Sources 234:201–207CrossRef Lee SH, Yoon CS, Amine K, Sun YK (2013) Improvement of long-term cycle performance of Li[Ni0.8Co0.15Al0.05]O2 by AlF3 coating. J Power Sources 234:201–207CrossRef
24.
Zurück zum Zitat Lee DJ, Scrosati B, Sun YK (2011) Ni3(PO4)2-coated Li[Ni0.8Co0.15Al0.05]O2 lithium battery electrode with improved cycle performance at 55 °C. J Power Sources 196(18):7742–7746CrossRef Lee DJ, Scrosati B, Sun YK (2011) Ni3(PO4)2-coated Li[Ni0.8Co0.15Al0.05]O2 lithium battery electrode with improved cycle performance at 55 °C. J Power Sources 196(18):7742–7746CrossRef
25.
Zurück zum Zitat Ryu KS, Lee SH, Koo BK, Lee JW, Kim KM, Park YJ (2008) Effects of Co3(PO4)2 coating on LiNi0.8Co0.16Al0.04O2 cathodes during application of high current. J Appl Electrochem 38(10):1385–1390CrossRef Ryu KS, Lee SH, Koo BK, Lee JW, Kim KM, Park YJ (2008) Effects of Co3(PO4)2 coating on LiNi0.8Co0.16Al0.04O2 cathodes during application of high current. J Appl Electrochem 38(10):1385–1390CrossRef
26.
Zurück zum Zitat Liu W, Hu G, Du K, Peng Z, Gao Y (2013) Enhanced storage property of LiNi0.8Co0.15Al0.05O2 coated with LiCoO2. J Power Sources 230:201–206CrossRef Liu W, Hu G, Du K, Peng Z, Gao Y (2013) Enhanced storage property of LiNi0.8Co0.15Al0.05O2 coated with LiCoO2. J Power Sources 230:201–206CrossRef
27.
Zurück zum Zitat Ju JH, Ryu KS (2011) Synthesis and electrochemical performance of Li(Ni0.8Co0.15Al0.05)0.8 (Ni0.5Mn0.5)0.2O2 with core–shell structure as cathode material for Li-ion batteries. J Alloy Compd 509(30):7985–7992CrossRef Ju JH, Ryu KS (2011) Synthesis and electrochemical performance of Li(Ni0.8Co0.15Al0.05)0.8 (Ni0.5Mn0.5)0.2O2 with core–shell structure as cathode material for Li-ion batteries. J Alloy Compd 509(30):7985–7992CrossRef
28.
Zurück zum Zitat Ito S, Fujiki S, Yamada T et al (2014) A rocking chair type all-solid-state lithium ion battery adopting Li2O–ZrO2 coated LiNi0.8Co0.15Al0.05O2 and a sulfide based electrolyte. J Power Sources 248:943–950CrossRef Ito S, Fujiki S, Yamada T et al (2014) A rocking chair type all-solid-state lithium ion battery adopting Li2O–ZrO2 coated LiNi0.8Co0.15Al0.05O2 and a sulfide based electrolyte. J Power Sources 248:943–950CrossRef
29.
Zurück zum Zitat Wu N, Wu H, Liu H, Zhang Y (2016) Solvothermal coating LiNi0.8Co0.15Al0.05O2 microspheres with nanoscale Li2TiO3 shell for long lifespan Li-ion battery cathode materials. J Alloy Compd 665:48–56CrossRef Wu N, Wu H, Liu H, Zhang Y (2016) Solvothermal coating LiNi0.8Co0.15Al0.05O2 microspheres with nanoscale Li2TiO3 shell for long lifespan Li-ion battery cathode materials. J Alloy Compd 665:48–56CrossRef
30.
Zurück zum Zitat Lim SN, Ahn W, Yeon SH, Park SB (2014) Enhanced elevated-temperature performance of Li[Ni0.8Co0.15Al0.05]O2 electrodes coated with Li2O–2B2O3 glass. Electrochim Acta 136:1–9CrossRef Lim SN, Ahn W, Yeon SH, Park SB (2014) Enhanced elevated-temperature performance of Li[Ni0.8Co0.15Al0.05]O2 electrodes coated with Li2O–2B2O3 glass. Electrochim Acta 136:1–9CrossRef
31.
Zurück zum Zitat Duan J, Dong P, Wang D, Li X, Xiao Z, Zhang Y, Hu G (2018) A facile structure design of LiNi0.90Co0.07Al0.03O2 as advanced cathode materials for lithium ion batteries via carbonation decomposition of NaAl(OH)4 solution. J Alloy Compd 739:335–344CrossRef Duan J, Dong P, Wang D, Li X, Xiao Z, Zhang Y, Hu G (2018) A facile structure design of LiNi0.90Co0.07Al0.03O2 as advanced cathode materials for lithium ion batteries via carbonation decomposition of NaAl(OH)4 solution. J Alloy Compd 739:335–344CrossRef
32.
Zurück zum Zitat Dong P, Wang D, Yao Y, Li X, Zhang Y, Ru J, Ren T (2017) Stabilizing interface layer of LiNi0.5Co0.2Mn0.3O2 cathode materials under high voltage using p-toluenesulfonyl isocyanate as film forming additive. J Power Sources 344:111–118CrossRef Dong P, Wang D, Yao Y, Li X, Zhang Y, Ru J, Ren T (2017) Stabilizing interface layer of LiNi0.5Co0.2Mn0.3O2 cathode materials under high voltage using p-toluenesulfonyl isocyanate as film forming additive. J Power Sources 344:111–118CrossRef
33.
Zurück zum Zitat Duan J, Hu G, Cao Y, Tan C, Wu C, Du K, Peng Z (2016) Enhanced electrochemical performance and storage property of LiNi0.815Co0.15Al0.035O2 via Al gradient doping. J Power Sources 326:322–330CrossRef Duan J, Hu G, Cao Y, Tan C, Wu C, Du K, Peng Z (2016) Enhanced electrochemical performance and storage property of LiNi0.815Co0.15Al0.035O2 via Al gradient doping. J Power Sources 326:322–330CrossRef
34.
Zurück zum Zitat Qiu Z, Zhang Y, Dong P, Xia S, Yao Y (2017) A facile method for synthesis of LiNi0.8Co0.15Al0.05O2 cathode material. Solid State Ion 307:73–78CrossRef Qiu Z, Zhang Y, Dong P, Xia S, Yao Y (2017) A facile method for synthesis of LiNi0.8Co0.15Al0.05O2 cathode material. Solid State Ion 307:73–78CrossRef
36.
Zurück zum Zitat Wang C, Shen W, Liu H (2014) Nitrogen–doped carbon coated LiV2(PO4)3 derived from a facile in situ fabrication strategy with ultrahigh-rate stable performance for lithium-ion storage. New J Chem 38(1):430–436CrossRef Wang C, Shen W, Liu H (2014) Nitrogen–doped carbon coated LiV2(PO4)3 derived from a facile in situ fabrication strategy with ultrahigh-rate stable performance for lithium-ion storage. New J Chem 38(1):430–436CrossRef
37.
Zurück zum Zitat Zhang J, Zhao Z, Xia Z, Dai L (2015) A metal-free bifunctional electrocatalyst for oxygen reduction and oxygen evolution reactions. Nat Nanotechnol 10(5):444–452CrossRef Zhang J, Zhao Z, Xia Z, Dai L (2015) A metal-free bifunctional electrocatalyst for oxygen reduction and oxygen evolution reactions. Nat Nanotechnol 10(5):444–452CrossRef
38.
Zurück zum Zitat Jiang L, Qu Y, Ren Z, Yu P, Zhao D, Zhou W, Wang L, Fu H (2015) In situ carbon-coated yolk–shell V2O3 microspheres for lithium-ion batteries. ACS Appl Mater Interfaces 7(3):1595–1601CrossRef Jiang L, Qu Y, Ren Z, Yu P, Zhao D, Zhou W, Wang L, Fu H (2015) In situ carbon-coated yolk–shell V2O3 microspheres for lithium-ion batteries. ACS Appl Mater Interfaces 7(3):1595–1601CrossRef
39.
Zurück zum Zitat Dai G, Yu M, Shen F, Cao J, Ni L, Chen Y, Tang Y, Chen Y (2016) Improved cycling performance of LiNi0.8Co0.15Al0.05O2/Al2O3 with core–shell structure synthesized by a heterogeneous nucleation-and-growth process. Ionics 22(11):2021–2026CrossRef Dai G, Yu M, Shen F, Cao J, Ni L, Chen Y, Tang Y, Chen Y (2016) Improved cycling performance of LiNi0.8Co0.15Al0.05O2/Al2O3 with core–shell structure synthesized by a heterogeneous nucleation-and-growth process. Ionics 22(11):2021–2026CrossRef
40.
Zurück zum Zitat He X, Du C, Shen B et al (2017) Electronically conductive Sb-doped SnO2 nanoparticles coated LiNi0.8Co0.15Al0.05O2 cathode material with enhanced electrochemical properties for Li-ion batteries. Electrochim Acta 236:273–279CrossRef He X, Du C, Shen B et al (2017) Electronically conductive Sb-doped SnO2 nanoparticles coated LiNi0.8Co0.15Al0.05O2 cathode material with enhanced electrochemical properties for Li-ion batteries. Electrochim Acta 236:273–279CrossRef
41.
Zurück zum Zitat Li H, Zhou H (2012) Enhancing the performances of Li-ion batteries by carbon-coating: present and future. Chem Commun 48(9):1201–1217CrossRef Li H, Zhou H (2012) Enhancing the performances of Li-ion batteries by carbon-coating: present and future. Chem Commun 48(9):1201–1217CrossRef
Metadaten
Titel
Improved cycle performance of nitrogen and phosphorus co-doped carbon coatings on lithium nickel cobalt aluminum oxide battery material
verfasst von
Peng Gao
Yunpeng Jiang
Yongming Zhu
Huili Hu
Publikationsdatum
06.04.2018
Verlag
Springer US
Erschienen in
Journal of Materials Science / Ausgabe 13/2018
Print ISSN: 0022-2461
Elektronische ISSN: 1573-4803
DOI
https://doi.org/10.1007/s10853-018-2275-7

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