自1970年代起，開始有許多研究針對有限自然資源的濫用情形提出預警，而工業革命後的大量資源耗用與世界人口快速增長更進一步的加快了資源耗用速度，包含金屬、礦物、石化等資源預期將於數十年內耗盡。為了延長資源利用的週期，以高效率運用資源的概念也隨之誕生，相較於過去不斷投入自然資源並產出產品的開放型經濟，封閉式產品循環開始受到關注，此即為最原始的循環經濟概念。封閉式循環系統中最重要的目標為: 更少的廢棄排放至循環外、循環系統的高適應能力、降低資源回收過程的能源消耗、盡可能保留資源的殘值，基於上述目標，發展高回收率(high recycle rate)、高適應性(high capability)、低能源消耗(low energy consumption)、高產品價值(high economy)的回收流程為實踐循環經濟的重要指標。
作為小型、高效率的儲能裝置，目前鋰電池被廣泛使用於消費性電子產品、電動載具與大型儲能系統中，由於其高能量密度、體積小、相對穩定的化學性質等特性，使鋰電池逐漸取代其他種類的二次電池，成為儲能市場主流，且由於其難以取代的各項優勢，預期鋰電池在未來十年內將會有更大的成長空間，特別在電動載具與儲能系統應用方面，由於單一系統內使用大量的鋰電池，預期將在未來數年內超越傳統消費性電子產品的鋰電池使用量。隨著鋰電池需求量大增，各國也開始將鋰電池生產原料視為戰略性資源的一環，並開始積極地進行資源開發與存量管控，但關鍵金屬礦產，如鈷、鎳等原料長期缺乏的隱憂仍導致市場期貨價格屢創新高。且礦產資源開採往往為礦產開採國帶來各種社會問題，致使國際對於使用乾淨礦產的聲量高漲。已開發國家逐漸由開採新資源的方向轉而聚焦於更有效的既有資源運用，主要方向包含降低特定金屬在產品中的使用比例與健全回收機制，訴求逐步降低對天然資源的依賴。
減碳觀念的普及使台灣自2010年起，興起一波電動車的熱潮，也進一步推升鋰電池的消費量，但消費量提升的同時，意味著電池的報廢與處理問題也變得更加棘手。根據預測，此波電池的淘汰周期最快將在五年後的2025年發生，但現今台灣仍未發展具規模的回收企業與系統，若廢棄電池未經過妥善的處理程序，直接進行掩埋、焚化處理，將會使內部高濃度的重金屬元素與有機溶劑滲透土壤、地下水，造成如空氣、水汙染等環境問題，也與最初推廣電動載具的環保目標背道而馳。因此，為了即將到來的電池淘汰周期，在本土發展高效率、低能量消耗與高產出價值的鋰電池回收流程為刻不容緩的要務。
為達成循環經濟主要目標，本研究嘗試結合濕法與火法冶金流程，提出改良的混合流程方案，著眼於結合火法的高泛用性、低成本，與濕法的低能源消耗、高產品價值等優勢，並同時改善傳統火法大量能源與造渣劑消耗，傳統濕法的高溶劑消耗、高成本、大量廢液產出等缺點，以發展兼具經濟性、減少能源消費與降低二次汙染的鋰電池回收製程為目標。
為檢驗流程成果與探討反應機制，本研究以流程整合的概念討論各階段參數對於下一階段結果的影響，使流程參數最佳化。為驗證高回收率、低溶劑消耗、產品高值化的目標，本研究選擇數個指標進行流程效益評估，分別為: 溶劑消費量、雜質含量、金屬回收率等，最終研究實驗結果顯示，銅、鐵-鎳合金回收率可達到95 %以上，並以金屬狀態回收，主要回收目標的鈷、鎳金屬回收率也可達90 %以上，並同時降低產品中主要雜質(鋁、銅)量最低至0.01 %以下，達成工業製造鋰電池標準，以再製電極材料前驅溶液狀態或共析出為金屬鹽類形式回收，並且，最終評估能源消耗與經濟效益結果皆優於傳統製造流程，研究成果符合循環經濟中的高回收效率、降低能源、溶劑消耗與產品高值化目標，並驗證了新式流程的可行性。

Circular economy brings a sustainable solution where waste component can be reapplied to manufacturing cycle. With the booming of electric vehicles & green energy trend, Li-ion batteries (LIB) attract lots of attention in these years, along with the developing of green energy technology, how to deal with the spent LIBs become a urgent task for local governments and enterprise.
On the other hands, considering the fast growth of demands of LIBs, end of life LIBs is most likely replacement for manufacturing new LIBs. Among LIBs components, lithium, cobalt, and natural graphite are of the most concern based on geological availabilities and unbalanced distribution, such instability of material supply chain made resource shortage getting worsen. Along with the LIBs booming, situation of shortage predicted to become even severe. if local recycling system not be established as soon as possible, supply chain of raw material would be getting vulnerable in the near future.
Both hydrometallurgical & pyrometallurgical are common method used in scaled recycling process, but there still have some disadvantages when applying hydro- or pyro- process individually, i.e., severe air pollution issue of high temperature pyro- process, waste liquid of hydro- process …etc.
In this work, a proposed process utilizes a combination of pyrometallurgical physical separation to recovery cobalt, nickel, manganese, lithium from cathode, and sorting copper, stainless steel from anode and battery cover. It was found that cathode elements were reduced in low temperature zone (450 ~ 600 ℃), furthermore, reduced metal shows lower impurity level in the following separating and leaching sections. As a whole, recycling rate can be enhanced to 88 %, Cu and Al contents can be reduced to only 0.01 wt%, means over than 99 % of impurities were removed, recycling rates of cathode Co, Ni, and Mn are 89.4, 89.8, and 94.3 %, respectively, where the impurity aluminum in product can be controlled to lower than 0.5 wt%. This proposed process provides an effective process to recycle spent NCM LIBs.

[1]中華民國統計資訊網，Retrieved：May, 30, 2021, from： https://statdb.dgbas.gov.tw/pxweb/Dialog/viewplus.asp?ma=EP0105A1A&ti=%25A9U%25A7%25A3%25B2M%25B2z%25AA%25AC%25AAp%25A6~&path=../PXfile/Environment/&lang=9&strList=L
[2]中華民國環保署事業廢棄物申報統計，Retrieved：May, 30, 2021, from：https://statis91.epa.gov.tw/epa/stmain.jsp?sys=220&ym=9600&ymt=10800&kind=21&type=1&funid=11058&cycle=4&outmode=0&compmode=0&outkind=3&fld0=1&fld4=1&cod00=1&rdm=yn3592ay
[3]政府間氣候變化專門委員會(IPCC)，Global warming of 1.5℃，Retrieved：May, 30, 2021, from：https://www.ipcc.ch/sr15/chapter/chapter-1/
[4] Julian M. Allwood, Chapter 30 - Squaring the Circular Economy: The Role of Recycling within a Hierarchy of Material Management Strategies, Editor(s): Ernst Worrell, Markus A. Reuter, Handbook of Recycling, Elsevier, 2014, p445-477
[5] M. Geissdoerfer, P. Savaget, N.M.P. Bocken, E. J. Hultink, “The Circular Economy – A new sustainability paradigm?”, J. Cleaner Prod., Vol. 143, 2017, p757-768
[6] S. Fujita, H. Akashi, M. Adachipatent, patent. JP3956584B2 : Secondary battery
[7] L. Li, J. B. Dunn, X. X. Zhang, L. Gaines, R. J. Chen, F. Wu, and K. Amine, “Recovery of metals from spent lithium-ion batteries with organic acids as leaching reagents and environmental assessment”, J. Power Sources, 233 (2013), 180.
[8] C. Hanisch, T. Loellhoeffel, J. Diekmann, K. J. Markley, W. Haselrieder, and A. Kwade, “Recycling of lithium-ion batteries: a novel method to separate coating and foil of electrodes”, J. Clean Prod., 108 (2015), 301.
[9] T. Zhang, Y. He, F. Wang, L. Ge, X. Zhu, and H. Li,” Chemical and process mineralogical characterizations of spent lithium-ion batteries: An approach by multi-analytical techniques”, Waste Manage., 34 (2014), 1051.
[10] J. Diekmann, C. Hanisch, L. Froboese, G. Schaelicke, T. Loellhoeffel, A.S. Foelster, A. Kwade,” Ecological Recycling of Lithium-Ion Batteries from Electric Vehicles with
Focus on Mechanical Processes”, J. Electrochem. Soc., 164 (2017), A6184.
[11] M. Grützke, X. Mönnighoff, F. Horsthemke, V. Kraft, M. Winter, S. Nowak, “Extraction of lithium-ion battery electrolytes with liquid and supercritical carbon dioxide and additional solvents”, RSC Adv., 5 (2015), 43209–43217
[12] C. P. Grey and J. M. Tarascon, “Sustainability and in situ monitoring in battery development”, Nat. Mater., 16 (2017), 45.
[13] A. Kwade, J. Diekmann (2018), “Recycling of Lithium-Ion Batteries : the LithoRec Way”, springer, p2-5
[14] F. Perdu (2016). Overview of existing and innovative batteries. Science and energy seminar. e-EPS, Les Houches.
[15] C. Pillot. (2017), The rechargeable battery market and main trends 2016–2025. International battery seminar & exhibit, Retrieved：April, 26, 2021, from：https ://www.avicenne.com/pdf/Fort_Lauderdale_Tutorial_C_Pillot_March2015.pdf.
[16] H. E. Melin, The lithium-ion battery end-of-life market, 2018, Circular Energy Storage
[17]電動機車網，Retrieved：June, 10, 2021, from：https://www.lev.org.tw/default.asp,
[18]吳笙卉、方家振, April, 2020, 工業雜誌400期，循環經濟專欄，鋰電池循環經濟(上)，
[19] C. Pillot. (2016), The worldwide rechargeable battery market 2015-2025, Avicenne Energy.
[20] U.S. Geological Survey, (2019), Mineral commodity summaries 2019: U.S. Geological Survey, 200 p., Retrieved：June, 10, 2021, from：https://pubs.er.usgs.gov/publication/70202434, https://doi.org/10.3133/70202434.
[21] London metal exchange, Retrieved：May, 25, 2021, from：https://www.lme.com/en-GB/Metals/Minor-metals/Cobalt#tabIndex=0
[22] JOGMEC (2020), 鉱物資源マテリアルフロー 2019, Retrieved from：http://mric.jogmec.go.jp/news/202005_mr-2/
[23] London metal exchange, Retrieved：May, 25, 2021, from：https://www.lme.com/Metals/Non-ferrous/Nickel#tabIndex=0
[24] M. Grützke, V. Kraft, B. Hoffmann, S. Klamor, J. Diekmann, A. Kwade, M. Winter, S. Nowak, “Aging investigations of a lithium-ion battery electrolyte from a field-tested hybrid electric vehicle”, J. Power Sources, Vol. 273 (2015), Pages 83-88,
[25] N. Vieceli, C. A. Nogueira, C. Guimaraes, M. F. C. Pereira, F. O. Durao, and F. Margarido, “Effects of mechanical activation on lithium extraction from a lepidolite ore concentrate”, Waste Manage., 71 (2018), 350.
[26] Y. Fu, Y. He, L. Qu, Y. Feng, J. Li, J. Liu, G. Zhang, and W. Xie, “Enhancement in leaching process of lithium and cobalt from spent lithium-ion batteries using benzenesulfonic acid system”, Waste Manage., Vol. 88 (2019), p191-199
[27] J. Hu, J. Zhang, H. Li, Y. Chen, and C. Wang, “A promising approach for the recovery of high value-added metals from spent lithium-ion batteries”, J. Power Sources, Vol. 351, (2017), p192-199,
[28] L. Li, Y. Bian, X. Zhang, Y. Yao, Q. Xue, E. Fan, F. Wu, and R. Chen, “A green and effective room-temperature recycling process of LiFePO4 cathode materials for lithium-ion batteries”, Waste Manage., Vol. 85 (2019), p437-444,
[29] Z. Li, J. Huang, B. Y. Liaw, V. Metzler, and J. Zhang, “A review of lithium deposition in lithium-ion and lithium metal secondary batteries”, J. Power Sources, Vol. 254 (2014), p168-182
[30] F. Gu, J. Guo, X. Yao et al, “An investigation of the current status of recycling spent lithium-ion batteries from consumer electronics in China”, J. Clean Prod., 161 (2017), p765-780
[31] F. Saloojee, J. Lloyd, Lithium battery recycling process. Department of Environmental affairs Development Bank of South Africa, 2015, (Project No. DB-074 (RW1/1016))
[32] X. Zeng, J. Li, L. Liu, “Solving spent lithium-ion battery problems in China: opportunities and challenges”, Renew Sustain Energy Rev., 52 (2015), p1759–1767.
[33] Cheret D, Santen S (2007) Battery recycling. U.S. Patent No.7,169,206
[34] Sonoc A, Jeswiet J, Soo VK, (2015) Opportunities to improve recycling of automotive lithium ion batteries. Procedia CIRP 29:752–757. https ://doi.org/10.1016/j.proci r.2015.02.039
[35] H. Pinegar, Y.R. Smith, “Recycling of End-of-Life Lithium Ion Batteries, Part I: Commercial Processes”, J. Sustain. Metall., 5 (2019), p402–416
[36] Tedjar F, Foudraz J-C (2010) Method for the mixed recycling of lithium-based anode batteries and cells. U.S. Patent No. US 7,820,317
[37] C. Hanisch, T. Loellhoeffel, J. Diekmann, K. J. Markley, W. Haselrieder, A. Kwade, “Recycling of lithium-ion batteries: a novel method to separate coating and foil of electrodes”, J. Clean Prod., Vol. 108, Part A (2015), p301-311,
[38] S. Krüger, C. Hanisch, A. Kwade, M. Winter, S. Nowak, “Effect of impurities caused by a recycling process on the electrochemical performance of Li [Ni0.33Co0.33Mn0.33] O2”, Journal of Electroanalytical Chemistry, Vol. 726 (2014), p91-96,
[39] Xianlai Zeng, Jinhui Li & Narendra Singh, “Recycling of Spent Lithium-Ion Battery: A Critical Review”, Critical Reviews in Environmental Science and Technology, 44:10 (2014), p1129-1165
[40] Z. Li, J. Huang, B. Y. Liaw, V. Metzler, and J. Zhang, “A review of lithium deposition in lithium-ion and lithium metal secondary batteries”, J. Power Sources, Vol. 254 (2014), p168-182
[41] G. Lombardo, B. Ebin, M. R. S. Foreman, B. M. Steenari, and M. Petranikova, “Chemical Transformations in Li-Ion Battery Electrode Materials by Carbothermic Reduction”, ACS Sustain. Chem. Eng., 7, 16 (2019), p13668-13679
[42] Jiang L, Wang Q, Sun J., “Electrochemical performance and thermal stability analysis of LiNixCoyMnzO2 cathode based on a composite safety electrolyte”, J. Hazard Mater., 351 (2018), p260-269
[43] David R. Gaskell, David E. Laughlin (2017), Introduction to the Thermodynamics of Materials 6th edition, Taylor and Francis Group, https://doi.org/10.1201/9781315119038
[44] L. Sun, K. Qiu, “Organic oxalate as leachant and precipitant for the recovery of valuable metals from spent lithium-ion batteries”. Waste Manag., 32(8) (2012), p1575-1582.
[45] L. Li, J. Ge, F. Wu, R. Chen, S. Chen, B. Wu, “Recovery of cobalt and lithium from spent lithium ion batteries using organic citric acid as leachant”, J Hazard Mater., 15;176(1-3) (2010), p288-293.
[46] X. Chen, H. Ma, C. Luo, T. Zhou, “Recovery of valuable metals from waste cathode materials of spent lithium-ion batteries using mild phosphoric acid”, J Hazard Mater., 326 (2017), p77-86.
[47] L. Li, L. Zhai, X. Zhang et al, “Recovery of valuable metals from spent lithium-ion batteries by ultrasonic-assisted leaching process”, J Power Sources, 262 (2014), p380–385.
[48] CK Lee, KI Rhee, “Preparation of LiCoO2 from spent lithium-ion batteries”, J Power Sources, 109 (2002), p17–21.
[49] W. Tang, X. Chen, T. Zhou et al, “Recovery of Ti and Li from spent lithium titanate cathodes by a hydrometallurgical process”, Hydrometallurgy, 147–148 (2014), p210–216.
[50] J. Nan, D. Han, X. Zuo, “Recovery of metal values from spent lithium-ion batteries with chemical deposition and solvent extraction”, J Power Sources, 152 (2005), p278–284.
[51] H. Wang, B. Friedrich, “Development of a Highly Efficient Hydrometallurgical Recycling Process for Automotive Li–Ion Batteries”, J. Sustain. Metall., 1 (2015), p168–178
[52] L. Li, L. Zhai, X. Zhang et al, “Recovery of valuable metals from spent lithium-ion batteries by ultrasonic-assisted leaching process”, J Power Sources, 262 (2014), p380–385.
[53] S. M. Shin, N. H. Kim, J. S. Sohn, D. H. Yang, Y. H. Kim, “Development of a metal recovery process from Li-ion battery wastes”, Hydrometallurgy, Vol. 79, Issues 3–4 (2005), p172-181,
[54] F. Pagnanelli, E. Moscardini, P. Altimari et al, “Leaching of electrodic powders from lithium ion batteries: Optimization of operating conditions and effect of physical pretreatment for waste fraction retrieval”, Waste Manage., 60 (2017), p706–715.
[55] Virolainen S, Fallah Fini M, Laitinen A, Sainio T, Solvent extraction fractionation of Li-ion battery leachate containing Li, Ni, and Co., Separation and Purification Technology, vol.179 (2017), p274–282.
[56] T. Suzuki, T. Nakamura, Y. Inoue, M. Niinae, J. Shibata, “A hydrometallurgical process for the separation of aluminum, cobalt, copper and lithium in acidic sulfate media”, Separation and Purification Technology, Vol.98 (2012), p396-401
[57] R. Weyhe (2013), in Recycling und Rohstoffe (Eds: K. J. Thome´-Kozmiensky, D. Goldmann), Bd. 6, Vivis Verlag, Nietwerder, p505-525.
[58] Doron Aurbach et al, “Studies of Aluminum-Doped LiNi0.5Co0.2Mn0.3O2: Electrochemical Behavior, Aging, Structural Transformations, and Thermal Characteristics”, J. Electrochem. Soc., 162 (2015), A1014
[59] J. Ren, R. Li, Y. Liu, Y. Cheng, D. Mu, R. Zheng, J. Liu, C. Dai, “The Impact of Aluminum Impurity on the Regenerated Lithium Nickel Cobalt Manganese Oxide Cathode Materials from Spent LIBs”. New J. Chem., 41 (2017), p10959−10965.
[60] S. Krüger, C. Hanisch, A. Kwade, M. Winter, S. Nowak, “Effect of impurities caused by a recycling process on the electrochemical performance of Li[Ni0.33Co0.33Mn0.33]O2”, J. Electroanal. Chem., 726 (2014), p91−96.
[61] R. Zhang, Y. Zheng, Z. Yao, P. Vanaphuti, X. Ma, S. Bong, M. Chen, Y. Liu, F. Cheng, Z. Yang, and Y. Wang, “Systematic Study of Al Impurity for NCM622 Cathode Materials”, ACS Sustainable Chemistry & Engineering, 8 (26) (2020), p9875-9884
[62] E. Mossali, N. Picone, L. Gentilini, O. Rodrìguez, J. M. Pérez, M. Colledani, “Lithium-ion batteries towards circular economy: A literature review of opportunities and issues of recycling treatments”, Journal of Environmental Management, Vol. 264 (2020), 110500
[63] M. Aoyama, Y. Amano, K. Inoue, S. Honda, S. Hashimoto, Y. Iwamoto, “Synthesis and characterization of lithium aluminate red phosphors”, Journal of Luminescence, Vol. 135 (2013), p211-215,
[64] Jim McDowall (2014), “A Guide to Lithium-Ion Battery Safety.”, Retrieved from：https://cmte.ieee.org/pes-essb/wp-content/uploads/sites43/2016/06/2015-WM-PN-A-Guide-to-Lithium-ion-safety-Jim-McDowall.pdf
[65] D.A. Ferreira, L.M.Z. Prados, D. Majuste, M.B. Mansur, “Hydrometallurgical separation of aluminium, cobalt, copper and lithium from spent Li-ion batteries”, J Power Sources, 187 (2009), p238–246
[66] Pierre R. Roberge (2008), Corrosion Engineering: Principles and Practice, McGraw-Hill Education.
[67] F. King, General corrosion in nuclear reactor components and nuclear waste disposal systems, Woodhead Publishing Limited, 2012
[68] Retrieved: June, 2, 2021 from：https://www.alibaba.com/?spm=a2700.galleryofferlist.scGlobalHomeHeader.10.2ad187d5B6lbtk
[69] Mizuno bank, 車載用LiBリサイクルは日本企業にとってビジネスチャンスになるか, 2018, Retrieved: June, 2, 2021, from：https://www.mizuhobank.co.jp/corporate/bizinfo/industry/sangyou/pdf/1062_08.pdf
[70] The world bank, GNI per capita, Atlas method (current US$), Retrieved: June, 2, 2021 from：https://data.worldbank.org/indicator/NY.GNP.PCAP.CD?order=wbapi_data_value_2014+wbapi_data_value+wbapi_data_value-last&sort=desc
[71] J.B. Dunn, L. Gaines, M. Barnes, J. Sullivan, and M. Wang (2014), Argonne National Laboratory, “Material and Energy Flows in the Materials Production, Assembly, and End-of-Life Stages of the Automotive Lithium-Ion Battery Life Cycle, Energy”, https://doi.org/10.2172/1044525
[72] Jo Dewulf, Geert Van der Vorst, Kim Denturck, Herman Van Langenhove, Wouter Ghyoot, Jan Tytgat, Kurt Vandeputte, “Recycling rechargeable lithium ion batteries: Critical analysis of natural resource savings”, Resources, Conservation and Recycling, Vol. 54, Issue 4 (2010), p229-234
[73] S. Jia, B. Mao, S. Liu, Q. Sun, “Calculation and Analysis of Transportation Energy Consumption Level in China”, Journal of Transportation Systems Engineering and Information Technology, Vol. 10, Issue 1 (2010), p22-27,
[74] List of common conversion factors (Engineering conversion factors) - IOR Energy Pty Ltd (archive.org), Retrieved: June, 2, 2021, from: https://web.archive.org/web/20100825042309/http://www.ior.com.au/ecflist.html
[75] Directive 2006/66/EC of the European Parliament and of the Council of the 6 September 2006 on batteries and accumulators and repealing Directive 91/157/EEC, Official Journal of the European Union. European Union, (2006), Retrieved: November, 13, 2015, from: https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2006:266:0001:0014:EN:PDF