Gel breaking-capacity reduction and reutilization of waste lithium anode coating slurry

doi:10.16085/j.issn.1000-6613.2023-1019

Abstract

Abstract:

Waste lithium anode coating slurry is hard to filtrate and also hard to be reutilized since it contains high water content, which is strongly stable with a wonderful colloid dispersion. The colloidal properties of this waste coating slurry were characterized, its high-efficiency rubber breaking separation mechanisms were discussed, and its reutilization as active carbon was also investigated. The electrostatic repulsion provided by the carboxyl anion (R-COO^-) produced by the dissociation of sodium carboxymethylcellulose (CMC-Na) and the spatial resistance formed between particles by styrene-butadiene rubber (SBR) were the fundamental reasons for the colloidal stability of waste slurry. The decrease in acidity effectively suppressed the dissociation of carboxymethyl cellulose sodium (CMC-Na) in the slurry, resulting in reduced adsorption of charged groups (R-COO^-) onto the surface of graphite particles. Consequently, the electrostatic repulsion between particles weakened, facilitating particle agglomeration and undermining the cross-linking effect of styrene-butadiene rubber (SBR). When pH was 2.0, the filtration constant of the waste slurry escalated to 0.0741m²/s, resulting in a remarkable 48 percentage point reduction in moisture content. X-ray three-dimensional microscopy analysis (X-CT) showed that while fine particles agglomerated and broken, the retained electrostatic repulsion could reduce the filtration resistance, promote the development of the filter cake pore structure, generate a large pore radius, and the seepage network of the long throat channel reduced the amount of water adsorbed by the filter cake pores. Moreover, the separated solid carbon material demonstrated impressive adsorption capacities of 435mg/g, 0.645mg/g and 87mg/g for methylene blue, chromium (Cr⁶⁺) and COD, respectively. These values adhered to the first-rate standards set forth in the “LY/T 3279—2021”.

Key words: lithium battery, colloid, agglomeration, coating slurry, filtration, reutilization

摘要：

锂电负极废涂布浆料含水率高、胶态分散稳定性强，难以过滤。本文研究了废涂布浆料的胶态特性，分析了废浆料的高效破胶分离机理，并对其资源化进行了初步探索。羧甲基纤维素钠（CMC-Na）解离产生的羧基负离子（R-COO^-）提供的静电斥力及苯乙烯-丁二烯橡胶（SBR）在颗粒间形成的空间位阻力是废浆料胶态稳定性的根本原因。酸度的降低能够抑制浆料中CMC-Na的解离，减少吸附于石墨颗粒表面的带电基团R-COO^-，削弱静电斥力，造成颗粒团聚，并破坏SBR的架桥作用。pH=2.0时，废浆料破胶过滤效率较佳，过滤常数为0.0741m²/s，含水率降低48个百分点；X射线三维显微成像分析（X-CT）表明细微颗粒团聚破胶的同时，保留的静电斥力能够降低过滤阻力，促进滤饼孔道结构的发育，生成大孔隙半径，长喉道的渗流网络减少滤饼孔道吸附水的量；分离所得固相碳材对亚甲基蓝、铬（Cr⁶⁺）、COD的吸附量分别为435mg/g、0.645mg/g、87mg/g，满足《工业水处理用活性炭技术指标及试验方法》（LY/T 3279—2021）优级品标准。

关键词: 锂电, 胶体, 团聚, 涂布浆料, 过滤, 资源化

CLC Number:

X789

ZENG Xiangfei, HAN Yunhui, LIN Fan, HUANG Rong, YU Xi, HUANG Yao, WANG Rong, SHU Jiancheng, CHEN Mengjun. Gel breaking-capacity reduction and reutilization of waste lithium anode coating slurry[J]. Chemical Industry and Engineering Progress, 2024, 43(8): 4664-4673.

曾祥菲, 韩昀晖, 林凡, 黄荣, 余茜, 黄瑶, 王蓉, 舒建成, 陈梦君. 锂电负极废涂布浆料破胶减容与资源化利用[J]. 化工进展, 2024, 43(8): 4664-4673.

Figures/Tables 14

References 27

1	THOMITZEK Matthias, SCHMIDT Oke, Fridolin RÖDER, et al. Simulating process-product interdependencies in battery production systems[J]. Procedia CIRP, 2018, 72: 346-351.
2	孙晓辉, 曾红燕, 李景康. 浅谈锂离子电池正极浆料的制备方法及其特性[J]. 浙江化工, 2022, 53(3): 12-16.
	SUN Xiaohui, ZENG Hongyan, LI Jingkang. Discussion on the preparation method and characteristics of lithium ion battery cathode slurry[J]. Zhejiang Chemical Industry, 2022, 53(3): 12-16.
3	黄金凤, 韩昀晖, 胡玲, 等. LiCoO₂材料的电化学制备及回收研究进展[J]. 化学工业与工程, 2021, 38(6): 34-45.
	HUANG Jinfeng, HAN Yunhui, HU Ling, et al. Advances in preparing and recycling lithium cobalt oxide materials by electrochemical method[J]. Chemical Industry and Engineering, 2021, 38(6): 34-45.
4	NATARAJAN Subramanian, BHATTARAI Roshan Mangal, SUDHAKARAN M S P, et al. Recycling of spent graphite and copper current collector for lithium-ion and sodium-ion batteries[J]. Journal of Power Sources, 2023, 577: 233170.
5	LEE Jin-Hyon, LEE Sangkyu, PAIK Ungyu, et al. Aqueous processing of natural graphite particulates for lithium-ion battery anodes and their electrochemical performance[J]. Journal of Power Sources, 2005, 147(1/2): 249-255.
6	席孝敏, 景希玮, 徐健, 等. CMC取代度对负极浆料流变性及分散稳定性的影响[J]. 华东理工大学学报(自然科学版), 2019, 45(5): 742-749.
	XI Xiaomin, JING Xiwei, XU Jian, et al. Effect of CMC on rheological properties and dispersion stability of anode slurry[J]. Journal of East China University of Science and Technology, 2019, 45(5): 742-749.
7	ZHANG Xiao, JU Zhengyu, ZHU Yue, et al. Multiscale understanding and architecture design of high energy/power lithium-ion battery electrodes[J]. Advanced Energy Materials, 2021, 11(2): 2000808.
8	孙仲振. SBR在锂离子电池中的影响[J]. 云南化工, 2020, 47(9): 80-82.
	SUN Zhongzhen. Effects of SBR in lithium ion batteries[J]. Yunnan Chemical Technology, 2020, 47(9): 80-82.
9	ZOU Song, WANG Shuai, ZHONG Hong, et al. Hydrophobic agglomeration of rhodochrosite fines in aqueous suspensions with sodium oleate[J]. Powder Technology, 2021, 377: 186-193.
10	KOLB Cara Greta, LEHMANN Maja, KULMER Dominik, et al. Modeling of the stability of water-based graphite dispersions using polyvinylpyrrolidone on the basis of the DLVO theory[J]. Heliyon, 2022, 8(12): e11988.
11	XIE Delong, WU Hua, ZACCONE Alessio, et al. Criticality for shear-induced gelation of charge-stabilized colloids[J]. Soft Matter, 2010, 6(12): 2692-2698.
12	AROSIO Paolo, XIE Delong, WU Hua, et al. Effect of primary particle morphology on the structure of gels formed in intense turbulent shear[J]. Langmuir, 2010, 26(9): 6643-6649.
13	于小鹏. JTMW305T型内齿形高剪切胶体磨的研制[J]. 山西交通科技, 2011(3): 82-84.
	YU Xiaopeng. The development of JTMW305T type high shear colloid mill[J]. Shanxi Science & Technology of Communications, 2011(3): 82-84.
14	郑帼, 王彩林, 孙玉. 胶体化泥浆化学固液的分离[J]. 天津工业大学学报, 2017, 36(3): 33-38.
	ZHENG Guo, WANG Cailin, SUN Yu. Separation for chemical solid-liquid of drilling slurry[J]. Journal of Tianjin Polytechnic University, 2017, 36(3): 33-38.
15	Siham EZ-ZAHRAOUI, SEMLALI AOURAGH HASSANI Fatima-Zahra, BOUHFID Rachid, et al. Strengthening effect of phosphate sludge by-product and styrene-butadiene rubber on the properties of high-density polyethylene composites[J]. Composites Part A: Applied Science and Manufacturing, 2023, 166: 107378.
16	KUANG Chaozhi, ZENG Guoshen, ZHOU Yangjian, et al. Integrating anodic sulfate activation with cathodic H₂O₂ production/activation to generate the sulfate and hydroxyl radicals for the degradation of emerging organic contaminants[J]. Water Research, 2023, 229: 119464.
17	SETHI Vinny, KAUR Manpreet, THAKUR Abhishek, et al. Unravelling the role of hemp straw derived cellulose in CMC/PVA hydrogel for sustained release of fluoroquinolone antibiotic[J]. International Journal of Biological Macromolecules, 2022, 222: 844-855.
18	SILVA Daniel José DA, WIEBECK Hélio. CARS-PLS regression and ATR-FTIR spectroscopy for eco-friendly and fast composition analyses of LDPE/HDPE blends[J]. Journal of Polymer Research, 2018, 25(5): 112.
19	KOSMULSKI Marek, Edward MĄCZKA. Zeta potential and particle size in dispersions of alumina in 50-50 w/w ethylene glycol-water mixture[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2022, 654: 130168.
20	张炜. α-Al₂O₃悬浮液体系稳定性及其失稳絮凝体破碎基础研究[D]. 北京: 北京科技大学, 2021.
	ZHANG Wei. A fundamental study on the stability of α-Al₂O₃ suspension system and fragment ation of denstabolized flocs[D]. Beijing: University of Science and Technology Beijing, 2021.
21	PARUCHURI Vamsi K, NGUYEN Anh V, MILLER Jan D. Zeta-potentials of self-assembled surface micelles of ionic surfactants adsorbed at hydrophobic graphite surfaces[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2004, 250(1/2/3): 519-526.
22	徐升华, 周宏伟. 胶体的聚集过程和胶体晶体的微重力研究[J]. 力学与实践, 2022, 44(6): 1470-1475.
	XU Shenghua, ZHOU Hongwei. Study on the aggregation process of colloid and microgravity of colloidal crystal[J]. Mechanics in Engineering, 2022, 44(6): 1470-1475.
23	徐新阳, 罗蒨. 表层过滤特性和沉降的关系研究[J]. 金属矿山, 2001(4): 25-27.
	XU Xinyang, LUO Qian. Study on the relationship between the characteristics of surface filtering and settling[J]. Metal Mine, 2001(4): 25-27.
24	LI Qiang, YUAN Xin, ZHANG Meng, et al. A modified agglomeration kernel model used for particle agglomeration[J]. Advanced Powder Technology, 2022, 33(1): 103349.
25	MARTÍNEZ RODRÍGUEZ Kerlyns, BOSSY Mireille, HENRY Christophe. Particle agglomeration in flows: Fast data-driven spatial decomposition algorithm for CFD simulations[J]. International Journal of Multiphase Flow, 2022, 149: 103962.
26	李晓道, 吴思麟, 姜朋明, 等. 基于LBM-DEM方法的泥浆过滤微观过程[J]. 科学技术与工程, 2023, 23(9): 3839-3848.
	LI Xiaodao, WU Silin, JIANG Pengming, et al. Microscopic process of slurry filtration based on LBM-DEM method[J]. Science Technology and Engineering, 2023, 23(9): 3839-3848.
27	赖凌峰. 明胶与羧甲基纤维素钠的复合凝聚作用及其微胶囊制备[D]. 无锡: 江南大学, 2017.
	LAI Lingfeng. Composite coagulation of gelatin and sodium carboxymethyl cellulose and preparation of microcapsules[D]. Wuxi: Jiangnan University, 2017.

pH	过滤时间 /min	滤液体积 /mL	透过率 /mL·min^-1	滤饼含水率 /%
1.0	8.40	143	17.02	48.47
1.5	12.06	144	11.94	52.14
2.0	13.01	142	10.91	46.97
2.5	15.06	141	9.36	51.69
3.0	18.31	142	7.76	51.32
6.0（原浆料）	—	0	0	95.00

pH	过滤时间 /min	滤液体积 /mL	透过率 /mL·min^-1	滤饼含水率 /%
1.0	8.40	143	17.02	48.47
1.5	12.06	144	11.94	52.14
2.0	13.01	142	10.91	46.97
2.5	15.06	141	9.36	51.69
3.0	18.31	142	7.76	51.32
6.0（原浆料）	—	0	0	95.00

样品	孔隙率/%	孔隙数	喉道数	平均孔隙半径/μm	平均喉道长度/μm
pH=1.0滤饼	7.95	6209	5476	52.20	105.36
pH=2.0滤饼	0.34	56	21	104.23	212.64

样品	孔隙率/%	孔隙数	喉道数	平均孔隙半径/μm	平均喉道长度/μm
pH=1.0滤饼	7.95	6209	5476	52.20	105.36
pH=2.0滤饼	0.34	56	21	104.23	212.64

污染物种类	吸附值/mg·g^-1	标准参考值/mg·g^-1
污染物种类	吸附值/mg·g^-1	优级品	合格品
碘	66	700	500
亚甲基蓝	435	120	90
铬（Cr⁶⁺）	0.645	0.5
COD	87	40	35