16 2 Vol 16 No 2 2010 5 ELECTROCHEMISTRY May 2010 1006-3471 2010 02-0185-07 1* 1 1 2 1 300384 2 300130 DSC GC /MS XRD Li 0 5 CoO 2 Li 0 5 CoO 2 O 2 CO 2 SEI TM912 9 A 0 1 mm s - 1 50 mv 1 2-5 1 3 6-8 DSC200PC NETZSCH / / 25 ~ 300 5 K min - 1 N 2 20 ml min - 1 / 1 6890N /5973 inter 1 1 GC-MS AGILENT GS-GASPRO 30 m 0 32 463446 mm i d 0 25 μm 250 LiCoO 2 PVDF Polyvinylidene Fluoride 96 2 2 by mass PVDF 94 4 2 by mass 1 0 mol L - 1 LiPF 6 / EC + EMC + DEC 1 1 1 by Vol 1 2 30 3 min 260 25 min - 1 5 min 1 8 ml min - 1 1 μl 20 1 D /max-2550 X XRD Cu K α 40 kv 40 ma 5 ~ 80 4 min - 1 2 1 a 2 1 b c d 2010-01-21 2010-03-25 09JCYBJC07200 * Tel 86-22 83716995 E-mail Lihe9701@ 126 com
186 2010 1 Fig 1 Fig 1 2 Schematic diagram of the battery impact testing machine for simulating internal short-circuit in cell a motor b locating device c impact head d battery base Fig 2 Relationship between the external temperature and experimental time in the internal short-circuit test of lithium ion batteries 2 2 3 LiCoO 2 Li 0 5 CoO 2 2 Li 0 5 CoO 2 DSC LiCoO 2 300 Li 0 5 CoO 2 170 Li 0 5 CoO 2 Li 0 5 CoO 2 GC /MS 1 4 100 150 Tab 1 1 % Relative percentage content of gas products in the reaction of simple cathode with electrolyte at different temperatures External temp / Air + CO + N 2 CO 2 CH 2 CH 2 CH 3 CH CH 2 CH 3 CH 2 F 100 59 3 40 66 0 04 150 45 17 53 41 0 71 0 22 0 48 180 0 8 91 7 5 1 0 2 1 7
2 187 3 Fig 3 3 DSC DSC curves of three cathode materials 180 Li 0 5 CoO 2 1 /2LiCoO 2 + 1 /6Co 3 O 4 + 1 /6O 2 6 5 /2O 2 + C 3 H 4 O 3 EC 3CO 2 + 2H 2 O 7 1 5 GC /MS 100 XRD 150 CO 2 CH 2 CH 2 LiPF 幑幐 6 LiF + PF 5 Lewis acid 2 C 4 H 8 O 3 EMC + PF 5 C 2 H 5 OCOOPF 4 + HF + C 2 H 4 3 C 4 H 8 O 3 EMC + PF 5 C 2 H 5 OCOOPF 4 + C 2 H 5 F 4 2C 2 H 5 OCOOPF 4 2PF 3 O + HF + C 2 H 5 F + CO 2 + C 3 H 6 5 LiPF 6 PF 5 EMC LiPF 6 60 PF 5 Lewis C 2 H 5 F 180 90% CO 2 Li 0 5 CoO 2 CO 2 4 O Fig 4 Photos of the simple cathode with plastic aluminum 2 Li 0 5 CoO 2 package after heating treatment at different temperatures Li 0 5 CoO 2 O 2 EC SEI 180 Li 0 5 CoO 2 CH 2 OCO 2 Li 2 Li 2 CO 3 + C 2 H 4 + CO 2 + Li 0 5 CoO 2 Co 3 O 4 LiCoO 2 1 /2O 2 1 180 Li 0 5 CoO 2 Li- CH 2 OCO 2 Li 2 SEI CoO 2 Co 3 O 4 O 2 CO 2 150 2 3 CH 3 CH 2 F CH 3 CH CH 2 6 LiC CH 2 CH 2 6 LiC 6 DSC EMCEC LiC 6 LiC 6
188 2010 5 Fig 5 XRD 6 XRD patterns of the simple cathode after heating treatment at different temperatures GC /MS 2 7 100 150 180 230 180 280 6 Fig 6 DSC DSC curves of various anode materials 7 Fig 7 Photos of the simple anode with plastic aluminum package after heating treatment at different temperatures 250 2 EC GC /MS PVDF Li 100 CH 4 CH 2 CH 2 250 SEI Li 3 180 EMC Li 2C 4 H 8 O 3 EMC + 2Li 2CH 3 CH 2 OCO 2 Li + Tab 2 2 % Relative percentage content of the gas products in reaction of simple anode with electrolyte at different temperatures t / Air + CO + N 2 CH 4 CH 3 CH 3 CO 2 CH 2 CH 2 CH 3 CH CH 2 CH 3 CH 2 F CH 3 CH 2 CH CH 2 100 99 44 0 24 0 32 150 34 02 0 84 1 77 49 2 10 23 3 4 0 2 0 16 180 71 2 0 47 0 77 21 39 4 4 1 6 0 17 230 87 69 0 17 0 42 7 69 2 21 1 02 0 09
2 189 2CH 4 8 CH CF n + nlif + n /2H 2 12 2 4 CO 2 CH 2 CH 2 CH 3 CH 2 F CH 3 CH CH 2 SEI SEI 1 ~ 5 CH 3 CH 3 CH 3 CH 2 2Li + C 4 H 8 O 3 EMC Li 2 CO 3 + C 3 H 8 10 3 180 230 < 230 SEI Li 280 7 25 6 10 39 >> 1 95 10 20 1 43 EC 10 6 > 0 6 10 5 C 3 H 4 O 3 EC + PF 5 PEO + nco 2 11 PVDF 8 2 PVDF Li CH 2 CF 2 n + nli CH 3 Li 2 2Li + C 3 H 4 O 3 EC Li 2 CO 3 + C 2 H 6 9 3 10 s 10 s Tab 3 3 Thermodynamic and dynamic parameters of various reactions in the batteries Reaction Temperature range / Exothermicquantity / Activation energy / J mol - 1 kj mol - 1 Pre-exponential factor /s - 1 Decomposition of SEI 100 1 5 10 4 2 85 10 5 7 88 10 36 Li x C 6 /Solvent 110 ~ 260 0 6 10 5 2 0 10 5 1 95 10 20 Li x C 6 /PVDF 250 ~ 350 1 0 10 5 1 67 10 5 1 79 10 13 Decomposition of Li x CoO 2 170 0 8 10 5 3 5 10 5 7 25 10 39 O 2 /Solvent 170 ~ 240 1 43 10 6 Decomposition of Solvent 120 ~ 280 1 5 10 4 2 74 10 5 5 14 10 25
190 2010 8 Fig 8 Variations of the external temperature of batteries with experimental time from 65 s to 85 s M Beijing Chemical Industry Press 2002 10 5 2 Spotnitz R Franklin J Abuse behavior of high-power A SEI SEI Sources 2006 155 401-414 CO 2 C 2 H 4 4 Zeng Yuqun Wu Kai Wang Deyu et al Overcharge investigation of lithium-ion polymer batteries J Journal PF 5 of Power Sources 2006 160 1302-1307 3 Li 0 5 CoO 2 SEI LiC 6 References 1 Wu Yuping Wan Chunrong Jiang Changyin et al Lithium ion second battery lithium-ion cells J Journal of Power Sources 2003 113 81-100 B 3 Balakrishnan P G Ramesh R Kumar T P Safety mechanisms in lithium-ion batteries J Journal of Power LiC 6 CH 4 5 Mandal B K Padhi A K Shi Zhong et al Thermal runaway inhibitors for lithium battery electrolytes J Jour- C 2 H 5 F C 3 H 6 C 3 H 8 nal of Power Sources 2006 161 1341-1345 6 Tang Chenming Wang Xingwei C Sha Yongxiang et al Over-charge characteristics of high-power 18650 Li-ion batteries J Chinese Li 0 5 CoO 2 Journal of Power Sources 2007 31 11 O 2 885-887 CO 2 7 Said Al-Hallaj Selman J R Thermal modeling of secondary lithium batteries for electric vehicle / hybrid electric vehicle applications J Journal of Power Sources D 2002 110 341-348 8 Tang Zhiyuan Guan Daoan Zhang LiC 6 Na et al Research on safety characteristics of high power lithium-ion batteries J Chemical Industry and Engineering Progress 2005 24 10 1098-1102 E
2 191 Failure Reaction Mechanism of Internal Short-Circuit for Lithium-ion Batteries LI He 1* YU Shen-jun 1 CHEN Zhi-kui 1 LIANG Guang-chuan 2 1 Tianjin Lishen Battery Joint-Stock CO LTD Tianjin 300384 China 2 Hebei University of Technology Tianjin 300130 China Abstract In this work the battery impact testing machine has been used to study the failure progress of internal short-circuit ISC for lithium ion batteries The reaction mechanisms between cathode /anode and electrolyte in the battery at different temperatures were characterized by differential scanning calorimetry DSC gas chro- matography /mass spectrometry GC /MS and X-ray diffraction XRD The experimental results show that the ISC failure of the battery was mainly due to the reaction between cathode Li 0 5 CoO 2 and electrolyte The decomposition and oxygen evolution reactions of cathode occurred when the temperature reached a certain value At the same time a fierce oxidation reaction occurred between oxygen and electrolyte giving out a large quantity of CO 2 gas and breaking aluminum can thus causing the battery exploded And the decomposition of SEI film and the initial reaction between anode and electrolyte were mainly to accumulating heat for the reaction between cathode and electrolyte Key words lithium ion battery internal short-circuit failure mechanism impact