Preparation and Performance of Al/TiO2 Composite Powder Anode Foils for Aluminum Capacitors

ZHOU Daiming; ZENG Xian; BIAN Jiatong; LIANG Libo; HUANG Hongzhu; CHEN Jianhui

doi:10.16490/j.cnki.issn.1001-3660.2025.22.015

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Surface Technology ›› 2025, Vol. 54 ›› Issue (22) : 159-169. DOI: 10.16490/j.cnki.issn.1001-3660.2025.22.015

Surface Functionalization

Preparation and Performance of Al/TiO₂ Composite Powder Anode Foils for Aluminum Capacitors

ZHOU Daiming¹, ZENG Xian¹, BIAN Jiatong¹, LIANG Libo^2*, HUANG Hongzhu², CHEN Jianhui²

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Abstract

The performance of aluminum powder anode foils which serve as critical components in aluminum electrolytic capacitors, is strongly affected by their microstructures, surface morphologies, and dielectric film compositions. The work aims to systematically investigate the effect of incorporating titanium dioxide (TiO₂) sol into the preparation of aluminum powder anode foils to enhance specific capacity while clarifying the underlying mechanisms. Scanning electron microscopy (SEM) observations revealed that the addition of TiO₂ sol into the slurry not only increased the porosity and pore size of the resulting foils, but also reduced the size of the sintering necks between powder particles. These structural modifications provided more active surface area for dielectric film growth and facilitated the subsequent formation of an Al/TiO₂ composite oxide layer, ultimately contributing to an improvement in the specific capacity. In order to further understand the physicochemical interactions during processing, complementary characterization techniques including energy-dispersive spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), and zeta potential analysis were employed. These results indicated that the introduction of TiO₂ sol into the slurry reduced the electrostatic repulsion between aluminum particles and TiO₂ nanoparticles, thereby improving dispersion stability and promoting intimate contact between the two phases. When the sintered powder foils were subsequently immersed in TiO₂ sol, additional deposition and infiltration of Ti species occurred, which facilitated further growth of a uniform Al/TiO₂ composite oxide film. The combination of slurry modification and post-sintering immersion acted synergistically to maximize the incorporation of TiO₂ and improve the electrochemical performance. The degree of Ti incorporation was quantitatively analyzed through inductively coupled plasma optical emission spectrometry (ICP-OES). The results demonstrated a progressive increase in Ti content with different treatments: 0wt.% in untreated aluminum powder foils, 0.15wt.% when TiO₂ sol was added to the slurry, 0.20wt.% when the sintered foils were immersed in TiO₂ sol, and 0.55wt.% when both sol addition and immersion were applied. These findings confirmed that high-dielectric TiO₂ was successfully introduced into the material system, and that the combined processing route was the most effective in achieving significant Ti enrichment. The impact of Ti incorporation on dielectric performance was further evaluated by measuring the dielectric loss characteristics of the composite foils. The results showed that the loss tangent increased with higher TiO₂ content. This behavior could be attributed to the fact that the breakdown field strength of TiO₂ was lower than that of Al₂O₃. As more TiO₂ was incorporated, the composite dielectric film became thicker but also contained more structural defects, which contributed to an overall deterioration in dielectric loss performance. Nevertheless, the trade-off between increased specific capacity and elevated dielectric loss highlighted the importance of optimizing TiO₂ incorporation levels. Electrochemical measurements confirmed the benefits of the dual-treatment approach on specific capacity. The untreated aluminum powder anode foil exhibited a specific capacity of 1.063 μF/cm². With only sol added to the slurry, the specific capacity increased slightly to 1.076 μF/cm². More significant improvement was observed when both slurry sol addition and surface immersion were employed, yielding the highest specific capacity of 1.206 μF/cm², which represented an 11.86% enhancement compared to the untreated foil. These results clearly demonstrated that TiO₂ sol treatment could effectively introduce high-dielectric components, modify the microstructure, and enhance the specific capacity of aluminum powder anode foils, although at the expense of somewhat increased dielectric loss. In summary, this study provides new insights into the role of TiO₂ sol in tailoring the microstructure and dielectric properties of aluminum powder anode foils. The combination of slurry modification and post-sintering sol immersion is shown to be the most effective strategy for maximizing Ti incorporation and improving specific capacity. While the increased dielectric loss associated with TiO₂ introduction remains a challenge, the overall improvement in capacity indicates the potential of this approach for further optimization in advanced capacitor applications.

Key words

aluminium electrolytic capacitor / high specific volume / Al/TiO₂ / powder sintering

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ZHOU Daiming, ZENG Xian, BIAN Jiatong, LIANG Libo, HUANG Hongzhu, CHEN Jianhui. Preparation and Performance of Al/TiO₂ Composite Powder Anode Foils for Aluminum Capacitors[J]. Surface Technology. 2025, 54(22): 159-169 https://doi.org/10.16490/j.cnki.issn.1001-3660.2025.22.015

References

[1] 王伟, 张蕾. 铝电解电容器用电极箔发展现状及市场预测[J]. 有色金属加工, 2021, 50(2): 9-10.
WANG W, ZHANG L.Present Situation and Prospect of Electrode Foil for Aluminum Electrolytic Capacitor[J]. Nonferrous Metals Processing, 2021, 50(2): 9-10.
[2] 王文宝, 秦力, 董连军, 等. 固体铝电容专用阳极铝箔的研究现状与发展方向[J]. 电子元件与材料, 2016, 35(7): 1-6.
WANG W B, QIN L, DONG L J, et al.Research Progress and Development Direction of Anode Foil for Aluminum Solid Capacitors[J]. Electronic Components and Materials, 2016, 35(7): 1-6.
[3] 徐友龙. 铝电解电容器[M]. 西安: 西安交通大学出版社, 2020: 196-210.
XU Y L.Aluminium Electrolytic Capacitor[M]. Xi'an: Xi'an Jiaotong University Press, 2020: 196-210.
[4] 平慧, 杜显锋, 马明波, 等. 高比表面积铝电解电容器用电极箔的研究进展[J]. 电子元件与材料, 2023, 42(8): 922-932.
PING H, DU X F, MA M B, et al.Research Progress of Electrode Foils for Aluminum Electrolytic Capacitors with High Specific Surface Area[J]. Electronic Components & Materials, 2023, 42(8): 922-932.
[5] 王立强, 胥珊娜, 王海丽, 等. 铝粉粒径对铝电解电容器用烧结箔孔隙及电性能的影响[J]. 电子元件与材料, 2022, 41(5): 457-462.
WANG L Q, XU S N, WANG H L, et al.Effect of Aluminum Powder Particle Size on Pores and Electrical Properties of Sintered Foil for Aluminum Electrolytic Capacitors[J]. Electronic Components and Materials, 2022, 41(5): 457-462.
[6] 平敏文, 目秦将志. 用于铝电解电容器的电极材料和制造该电极材料的方法: CN102017034B[P].2016-01-27.
PING M W, MU Q J Z. Electrode Material for Aluminum Electrolytic Capacitors and Its Manufacturing Methods: CN102017034B[P].2016-01-27.
[7] MEHATA M, MURAMATSU K, TAIRA T. Chemical-Conversion Foil for Positive Electrode of Aluminum Electrolytic Capacitor, Electrode Material for Positive Electrode of Aluminum Electrolytic Capacitor,Method for Manufacturing Same: Japan, 2016158493.A[P].2016-10-06.
[8] 王银华, 杨军, 陈建军, 等. SrTiO₃复合氧化膜对铝阳极箔比容的影响[J]. 功能材料与器件学报, 2007, 13(4): 362-366.
WANG Y H, YANG J, CHEN J J, et al.Effect of SrTiO₃ Composite Oxide Film on Specific Capacitance of Aluminum Anode[J]. Journal of Functional Materials and Devices, 2007, 13(4): 362-366.
[9] 李晓洁. TiO₂-Al₂O₃复合氧化膜对铝电解电容器阳极箔比容的影响[D]. 柳州: 广西科技大学, 2017: 47-49.
LI X J.Effect of TiO₂-Al₂O₃ composite oxide film on the specific capacity of aluminum electrolytic capacitor anode foil[D]. Liuzhou: Guangxi University of Science and Technology, 2017: 47-49.
[10] 张帅伟. 复合氧化膜对高压阳极腐蚀铝箔比电容的影响[D]. 郑州: 郑州大学, 2013: 25-42.
ZHANG S W.Influence of composite oxide film for high voltage anode corrosion aluminum foil special capacitance[D]. Zhengzhou: Zhengzhou University, 2013: 25-42.
[11] LI M X, ZUO Z Q, XIE N, et al.Effect of Sintered Aluminum Powder Layer Structure on Properties of Sintered Anode Aluminum Foil[J]. Materials Chemistry and Physics, 2024, 318: 129278.
[12] BAI G Z, WANG C R, WANG F, et al.Tunable Electrical and Mechanical Properties of Anode Foils for Aluminum Electrolytic Capacitors Prepared by Additive Manufacturing Technology[J]. Journal of Materials Research and Technology, 2024, 30: 9647-9655.
[13] BAI G Z, CHEN Z B, LIU J, et al.Microstructure Evolution and Performance Enhancement of Sintered Aluminum Foils for Aluminum Electrolytic Capacitors[J]. Journal of Electronic Materials, 2024, 53(4): 2026-2039.
[14] DU X F, XU Y L.Formation of Al₂O₃-BaTiO₃ Nanocomposite Oxide Films on Etched Aluminum Foil by Sol-Gel Coating and Anodizing[J]. Journal of Sol-Gel Science and Technology, 2008, 45(1): 57-61.
[15] 杜显锋, 李响, 熊礼龙. 一种具有多级混合结构的多孔阳极铝箔的制备方法: CN111627714B[P].2021-08-13.
DU X F, LI X, XIONG L L. A Preparation Method for Porous Anode Aluminum Foil with Multi-stage Mixed Structure: CN111627714B[P].2021-08-13.
[16] WANG J P, CHENG F Y, DU X F, et al.Preparation of Al₂O₃/TiO₂ Composite Film with High Specific Capacitance by Surface Self-Assembly Method[J]. Journal of Inorganic Materials, 2018, 33(6): 617.
[17] YAN H W, CANNON W R, SHANEFIELD D J.Evolution of Carbon during Burnout and Sintering of Tape-Cast Aluminum Nitride[J]. Journal of the American Ceramic Society, 1993, 76(1): 166-172.
[18] 韩振宇, 马莒生, 徐忠华, 等. 低温共烧玻璃陶瓷基板烧结过程分析Ⅰ低温区有机物的分解及变化[J]. 功能材料, 2001, 32(3): 272-274.
HAN Z Y, MA J S, XU Z H, et al.Sintering Process Analysis of Low Temperature Cofired CeramicsⅠOrganics Pyrolysis in Low Temperature Phase[J]. Journal of Functional Materials, 2001, 32(3): 272-274.
[19] 桂如峰. 氮化铝陶瓷的流延成型及烧结体性能研究[D]. 武汉: 华中科技大学, 2019.
GUI R F.Study on tape casting and sintering properties of aluminum nitride ceramics[D]. Wuhan: Huazhong University of Science and Technology, 2019.
[20] ZENG X, BIAN J T, LIANG L B, et al.Preparation and Characterization of Anode Foil for Aluminum Electrolytic Capacitors by Powder Additive Manufacturing[J]. Powder Technology, 2023, 426: 118602.
[21] PIECZONKA T.Disruption of an Alumina Layer during Sintering of Aluminium in Nitrogen[J]. Archives of Metallurgy and Materials, 2017, 62(2): 987-992.
[22] WATANABE K, SAKAIRI M, TAKAHASHI H, et al.Formation of Composite Oxide Films on Aluminum by Sol-Gel Coating and Anodizing—For the Development of High Performance Aluminum Electrolytic Capacitors—[J]. Electrochemistry, 2001, 69(6): 407-413.
[23] CHEN J J, FENG Z S, JIANG M L, et al.The Effect of Anodizing Voltage on the Electrical Properties of Al-Ti Composite Oxide Film on Aluminum[J]. Journal of Electroanalytical Chemistry, 2006, 590(1): 26-31.
[24] 赵静, 王天鹏, 马坤松, 等. 磁致涡流效应对化成铝箔Al₂O₃-TiO₂复合膜结构及性能的影响[J]. 中国表面工程, 2018, 31(6): 63-72.
ZHAO J, WANG T P, MA K S, et al.Effects of Magnetohydrodynamic on Structure and Performance of Al₂O₃-TiO₂ Composite Oxide Film for Formed Aluminum Foil[J]. China Surface Engineering, 2018, 31(6): 63-72.
[25] DU X F, LIN B G, LI B, et al.Surface Modification of Al Foils for Aluminum Electrolytic Capacitor[J]. Advanced Functional Materials, 2017, 27(11): 1606042.
[26] 杜菲菲, 陈泉源. TiO₂/活性炭复合纳米纤维膜的制备及表征[J]. 材料导报, 2011, 25(20): 53-58.
DU F F, CHEN Q Y.Preparation and Characterization of TiO₂/Activated Carbon Composite Nano-Fiber Membrane[J]. Materials Reports, 2011, 25(20): 53-58.
[27] 张钱献, 郑国渠, 蔡超, 等. 阳极氧化铝作为铝电解电容器阳极箔用的研究[J]. 功能材料, 2011, 42(6): 1071-1074.
ZHANG Q X, ZHENG G Q, CAI C, et al.Research on the Anodic Aluminum Oxide as Anodic Foil of Aluminum Electrolytic Capacitor[J]. Journal of Functional Materials, 2011, 42(6): 1071-1074.
[28] 尹子豪, 韩泽祖, 赵晔航, 等. 石墨烯对铝粉烧结式阳极箔的影响研究[J]. 电子元件与材料, 2021, 40(11): 1067-1071.
YIN Z H, HAN Z Z, ZHAO Y H, et al.Effect of Graphene on Aluminum Powder Sintered Anode Foil[J]. Electronic Components and Materials, 2021, 40(11): 1067-1071.
[29] 班朝磊, 邵鑫, 王长征, 等. 铝箔表面Al₂O₃-ZrO₂复合阳极氧化膜的制备与性能[J]. 材料热处理学报, 2013, 34(12): 161-165.
BAN C L, SHAO X, WANG C Z, et al.Formation and Properties of Al₂O₃-ZrO₂ Composite Anodic Oxide Film on Al Foil[J]. Transactions of Materials and Heat Treatment, 2013, 34(12): 161-165.
[30] GONG X H, YANG R, HE G L, et al.Preparation and Properties of High Specific Capacitance TiO₂-Al₂O₃ Composite Powder-Layered Anode Aluminum Foils[J]. Materials Letters, 2025, 399: 138985.