Review on Microstructure Control and Performance Improvement of ZnO Varistors
He Junjia1, Song Li1, Zhou Benzheng1, Fu Zhiyao2, Wang Chaofan1, Zhang Xiaoxuan1
1. State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China; 2. State Key Laboratory of Disaster Prevention and Mitigation of Power Grid Transmission and Transformation Equipment State Grid Hunan Electric Power Co. Ltd Disaster Prevention and Mitigation Center Changsha 410129 China
Abstract:As the core component of metal oxide arresters, the ZnO varistor has always been the focus of research. In the face of the new power system with the wide application of new energy in the future, ZnO varistors should not be limited to the optimization of small current characteristics. In some specific situations, the performance of varistors with high potential gradient, large flow capacity, and low residual voltage ratio is the focus of future attention. This paper summarizes the research on the microstructure regulation and performance improvement of the ZnO varistor from the perspective of traditional mechanical powder mixing and surface coating, and considers the research works that need to be carried out under the coating route, hoping to provide some references for research in related fields. For a long time, people have mainly improved the performance of the ZnO varistor by improving the material formula, improving the sintering process, and optimizing the powder preparation according to the process route of mechanical powder mixing and sintering. Based on the traditional formula, it was found that the doping of rare earth elements can effectively control the grain size, thus improving the uniformity of the microstructure and the potential gradient of the varistor. Using ultrafine powder also reduced the particle size and improved the microstructure uniformity. The new sintering techniques, such as cold sintering, flash sintering, and spark plasma sintering, can ensure the compacting of the porcelain body and reduce the sintering temperature. These new technologies have played an important role in improving the performance of ZnO varistors, but the potential for further improvement is limited. Surface coating modification technology has been tried in the research field of ZnO varistors. In the initial exploratory experiments, one or more elements were coated on the surface of ZnO by salts corresponding to their oxides to form the core-shell structure. The prepared ZnO varistor samples had a smaller grain size and narrower distribution, which was beneficial to improve the microstructure uniformity. Different from mechanical powder mixing sintering, the core-shell structure formed by cladding can form a heating mode with a specific temperature field structure on the billet with the help of the outer cladding during sintering, rather than relying on the temperature field of the furnace itself to directly act on the billet, which may have a better control effect on the structure formed by sintering. All these indicate that surface coating technology has a specific potential to improve the performance of ZnO varistors. However, as this kind of research is still in the early stage, much research is still needed on the following aspects: (1) Determine the coating element system suitable for ZnO to make the research work systematic; (2) Optimize the key process from coated powder to sheets, such as uniform dispersion of coated powder and optimization of the sintering system; (3) Sum up the coated ZnO varistor performance evolution law, providing the basis for performance control; (4) Explore the influence of microscopic parameters on the macroscopic electrical properties, give a reasonable deep mechanism from the microscopic level, and put forward an effective method to customize the performance of the ZnO varistor; (5) The calculation of ZnO surface adsorption by first principles can play a guiding role in selecting the coating body and then designing the surface coating structure.
何俊佳, 宋丽, 周本正, 付志瑶, 王超凡, 张小旋. ZnO压敏电阻微观结构调控与性能提升研究综述[J]. 电工技术学报, 2023, 38(20): 5605-5619.
He Junjia, Song Li, Zhou Benzheng, Fu Zhiyao, Wang Chaofan, Zhang Xiaoxuan. Review on Microstructure Control and Performance Improvement of ZnO Varistors. Transactions of China Electrotechnical Society, 2023, 38(20): 5605-5619.
[1] 黄海龙, 胡志良, 代万宝, 等. 海上风电发展现状及发展趋势[J]. 能源与节能, 2020(6): 51-53. Huang Hailong, Hu Zhiliang, Dai Wanbao, et al.Development status and trend of offshore wind power[J]. Energy and Conservation, 2020(6): 51-53. [2] 高晨, 赵勇, 汪德良, 等. 海上风电机组电气设备状态检修技术研究现状与展望[J]. 电工技术学报, 2022, 37(增刊1): 30-42. Gao Chen, Zhao Yong, Wang Deliang, et al.Research status and prospect of condition based maintenance technology for offshore wind turbine electrical equipment[J]. Transactions of China Electrotechnical Society, 2022, 37(S1): 30-42. [3] 陈泽西, 孙玉树, 张妍, 等. 考虑风光互补的储能优化配置研究[J]. 电工技术学报, 2021, 36(增刊1): 145-153. Chen Zexi, Sun Yushu, Zhang Yan, et al.Research on energy storage optimal allocation considering com- plementarity of wind power and PV[J]. Transactions of China Electrotechnical Society, 2021, 36(S1): 145-153. [4] 许汉平, 杨炜晨, 张东寅, 等. 考虑换相失败相互影响的多馈入高压直流系统换相失败判断方法[J]. 电工技术学报, 2020, 35(8): 1776-1786. Xu Hanping, Yang Weichen, Zhang Dongyin, et al.Commutation failure judgment method for multi- infeed HVDC systems considering the interaction of commutation failures[J]. Transactions of China Elec- trotechnical Society, 2020, 35(8): 1776-1786. [5] 罗新, 黄学民, 刘春涛, 等. 换流站交流滤波器用避雷器频繁动作原因分析[J]. 电瓷避雷器, 2019(3): 159-164. Luo Xin, Huang Xuemin, Liu Chuntao, et al.Analysis of reasons for the frequent action of arrester in AC filter in converter station[J]. Insulators and Surge Arresters, 2019(3): 159-164. [6] 程宽, 赵洪峰, 周远翔. B2O3掺杂对直流ZnO压敏电阻老化特性的影响[J]. 电工技术学报, 2022, 37(13): 3413-3421. Cheng Kuan, Zhao Hongfeng, Zhou Yuanxiang.Effect of B2O3 doping on the aging characteristics of DC ZnO varistor ceramics[J]. Transactions of China Electrotechnical Society, 2022, 37(13): 3413-3421. [7] Gupta T K.Application of zinc oxide varistors[J]. Journal of the American Ceramic Society, 1990, 73(7): 1817-1840. [8] 何金良. 金属氧化物压敏电阻: 从微观结构到宏观特性[M]. 北京: 清华大学出版社, 2019. [9] 王振林, 李盛涛. 氧化锌压敏陶瓷制造及应用[M]. 北京: 科学出版社, 2009. [10] Gupta T K.Microstructural engineering through donor and acceptor doping in the grain and grain boundary of a polycrystalline semiconducting cera- mic[J]. Journal of Materials Research, 1992, 7(12): 3280-3295. [11] Morris W, Cahn J.Adsorption and microphases at grain boundaries in non-ohmic zinc oxide ceramics containing bismuth oxide[C]//1974 4th Bolton Landing conference on Grain Boundaries in Engineering Materials, Baton Rouge, LA, 1975: 223-233. [12] Mukae K, Tsuda K, Nagasawa I.Non-ohmic pro- perties of ZnO-rare earth metal oxide-Co3O4 cera- mics[J]. Japanese Journal of Applied Physics, 1977, 16(8): 1361-1368. [13] Tsai J K, Wu T B.Non-ohmic characteristics of ZnO- V2O5 ceramics[J]. Journal of Applied Physics, 1994, 76(8): 4817-4822. [14] Sendi R K.Effects of different compositions from magnetic and nonmagnetic dopants on structural and electrical properties of ZnO nanoparticles-based varistor ceramics[J]. Solid State Sciences, 2018, 77: 54-61. [15] Suzuki H, Bradt R C.Grain growth of ZnO in ZnO-Bi2O3 ceramics with TiO2 additions[J]. Journal of the American Ceramic Society, 1995, 78(5): 1354-1360. [16] Daneu N, Rečnik A, Bernik S.Grain growth control in Sb2O3-doped zinc oxide[J]. Journal of the Ameri- can Ceramic Society, 2003, 86(8): 1379-1384. [17] He Jinliang, Long Wangcheng, Hu Jun, et al.Nickel oxide doping effects on electrical characteristics and microstructural phases of ZnO varistors with low residual voltage ratio[J]. Journal of the Ceramic Society of Japan, 2011, 119(1385): 43-47. [18] Meng Pengfei, Hu Jun, He Jinliang.Low-residual- voltage ZnO varistor ceramics improved by multiple doping with gallium and indium[J]. Materials Letters, 2017, 195: 209-212. [19] Bernik S, Maček S, Ai B.Microstructural and elec- trical characteristics of Y2O3-doped ZnO-Bi2O3-based varistor ceramics[J]. Journal of the European Ceramic Society, 2001, 21(10/11): 1875-1878. [20] Ashraf M A, Bhuiyan A H, Hakim M A, et al.Microstructure and electrical properties of Ho2O3 doped Bi2O3-based ZnO varistor ceramics[J]. Physica B: Condensed Matter, 2010, 405(17): 3770-3774. [21] 翁俊梅, 姜胜林, 许毓春, 等. Bi2O3和Sb2O3的预复合对ZnO压敏电阻性能的影响[J]. 电子元件与材料, 2012, 31(10): 12-15. Weng Junmei, Jiang Shenglin, Xu Yuchun, et al.Effects of pre-compounding of Bi2O3 and Sb2O3 on the properties of ZnO varistor[J]. Electronic Com- ponents and Materials, 2012, 31(10): 12-15. [22] Higashi Y, Koga E.Barrier formation of single junctions with oxidation in SrCoO3-doped ZnO varistors sintered in a reducing atmosphere[J]. Journal of the Ceramic Society of Japan, 2019, 127(12): 912-917. [23] 王瀛洲. 施主掺杂对氧化锌压敏陶瓷电性能的影响[D]. 广州: 华南理工大学, 2018. [24] Cheng Xuanzhong, Lu Zhenya, Liu Xingyue, et al.Improvement of surge current performances of ZnO varistor ceramics via C3N4-doping[J]. Journal of the European Ceramic Society, 2020, 40(6): 2390-2395. [25] Hembram K, Rao T N, Ramakrishana M, et al.Influence of CaO doping on phase, microstructure, electrical and dielectric properties of ZnO varistors[J]. Journal of Alloys and Compounds, 2020, 817: 152700. [26] Bernik S, Bernard J, Daneu N, et al.Microstructure development in low-antimony oxide-doped zinc oxide ceramics[J]. Journal of the American Ceramic Society, 2007, 90(10): 3239-3247. [27] 闫绳波. 基于固相合成工艺的高压ZnO压敏电阻器的配方研究[D]. 西安: 西安电子科技大学, 2013. [28] 安群力. 提高ZnO压敏电阻片电位梯度和降低其残压比的工艺措施[C]//电工陶瓷第七次学术年会暨学术交流会论文集, 2001: 109-110. [29] 陈青恒, 何金良, 谈克雄, 等. 提高氧化锌非线性电阻片通流容量的研究[J]. 电瓷避雷器, 2003(5): 26-28, 33. Chen Qingheng, He Jinliang, Tan Kexiong, et al.The study of improving the energy absorption capability of ZnO varistor[J]. Insulators and Surge Arresters, 2003(5): 26-28, 33. [30] 石成利, 刘国. 电子陶瓷材料的研究应用现状及其发展趋势[J]. 陶瓷, 2008(3): 11-16. Shi Chengli, Liu Guo.Current status for research and application and development trends on electronic ceramics[J]. Ceramics, 2008(3): 11-16. [31] 汪涛, 齐国权. 高压ZnO压敏电阻陶瓷材料研究进展[J]. 中国陶瓷, 2011, 47(12): 1-4, 7. Wang Tao, Qi Guoquan.The developments of high voltage ZnO varistors[J]. China Ceramics, 2011, 47(12): 1-4, 7. [32] Chu Shengyuan, Yan T M, Chen Shenli.Analysis of ZnO varistors prepared by the Sol-gel method[J]. Ceramics International, 2000, 26(7): 733-737. [33] 章会良, 曹全喜, 宋建军, 等. 高能氧化锌压敏元件研究[J]. 电子元件与材料, 2007, 26(10): 51-53. Zhang Huiliang, Cao Quanxi, Song Jianjun, et al.Research on ZnO varistor with high capability[J]. Electronic Components and Materials, 2007, 26(10): 51-53. [34] 梁烛, 倪凯凯, 代礼彬, 等. 纳米Bi2O3对ZnO压敏陶瓷性能的影响[J]. 广州化工, 2018, 46(8): 49-50, 85. Liang Zhu, Ni Kaikai, Dai Libin, et al.Effect of nano-Bi2O3 on electrical properties of ZnO varistor ceramics[J]. Guangzhou Chemical Industry, 2018, 46(8): 49-50, 85. [35] Liu Wenfeng, Zhang Lei, Kong Fanyi, et al.Enhanced voltage gradient and energy absorption capability in ZnO varistor ceramics by using nano-sized ZnO powders[J]. Journal of Alloys and Compounds, 2020, 828: 154252. [36] 赵永红, 郭建平, 乔爱平, 等. 氧化锌压敏陶瓷纳米复合材料的制备及表征[J]. 电瓷避雷器, 2004(3): 29-31, 35. Zhao Yonghong, Guo Jianping, Qiao Aiping, et al.The preparation & evaluation of nano compound powder for ZnO voltage-sensitive ceramic[J]. Insulators and Surge Arresters, 2004(3): 29-31, 35. [37] 霍建华. 烧成气氛对氧化锌压敏电阻器电性能的影响[J]. 电瓷避雷器, 2000(1): 35-38. Huo Jianhua.Impact of firing atmosphere on electrical properties of ZnO varistors[J]. Insulators and Surge Arresters, 2000(1): 35-38. [38] 侯清健, 徐国跃, 赵毅, 等. 烧结温度和热处理对ZnO压敏陶瓷的影响[J]. 电瓷避雷器, 2004(5): 36-38, 42. Hou Qingjian, Xu Guoyue, Zhao Yi, et al.Effect of sintering temperature and heat-treatment on ZnO varistor ceramics[J]. Insulators and Surge Arresters, 2004(5): 36-38, 42. [39] Metz R, Delalu H, Vignalou J R, et al.Electrical properties of varistors in relation to their true bismuth composition after sintering[J]. Materials Chemistry and Physics, 2000, 63(2): 157-162. [40] 康雪雅, 常爱民, 韩英, 等. ZnO压敏陶瓷的微波烧结[J]. 无机材料学报, 1998, 13(5): 751-754. Kang Xueya, Chang Aimin, Han Ying, et al.Micro- wave sintering of ZnO varistor ceramics[J]. Journal of Inorganic Materials, 1998, 13(5): 751-754. [41] Chen I W, Wang Xiaohui.Sintering dense nano- crystalline ceramics without final-stage grain growth[J]. Nature, 2000, 404(6774): 168-171. [42] Cologna M, Rashkova B, Raj R.Flash sintering of nanograin zirconia in <5 s at 850 ℃[J]. Journal of the American Ceramic Society, 2010, 93(11): 3556-3559. [43] Wu Angxuan, Zhu Zhixiang, Wang Xilin, et al.High- performance ZnO varistor ceramics prepared by arc- induced flash sintering with low energy consumption at room temperature[J]. High Voltage, 2022, 7(2): 222-232. [44] Guo Jing, Guo Hanzheng, Baker A L, et al.Cold sintering: a paradigm shift for processing and integration of ceramics[J]. Angewandte Chemie International Edition, 2016, 55(38): 11457-11461. [45] Jing Yang, Luo Nengneng, Wu Shaohai, et al.Remarkably improved electrical conductivity of ZnO ceramics by cold sintering and post-heat-treatment[J]. Ceramics International, 2018, 44(16): 20570-20574. [46] Ning Jiangli, Jiang Daming, Kim K H, et al.Influence of texture on electrical properties of ZnO ceramics prepared by extrusion and spark plasma sintering[J]. Ceramics International, 2007, 33(1): 107-114. [47] Matsuoka M.Nonohmic properties of zinc oxide ceramics[J]. Japanese Journal of Applied Physics, 1971, 10(6): 736. [48] 梁毓锦. 电力用氧化锌避雷器[J]. 电瓷避雷器, 1979(4): 36-47. Liang Yujin.Zinc oxide arrester for electric power[J]. Insulators and Surge Arresters, 1979(4): 36-47. [49] 汪仁根. 全国ZnO阀片摸底试验结果分析[J]. 中国电瓷, 1984(5): 1-9, 22. Wang Rengen.Analysis of the national ZnO valve plate test results[J]. China Electric Ceramics, 1984(5): 1-9, 22. [50] 严幼良, 丁华忠, 苟雅江. 提高氧锌电阻片性能的研究[J]. 中国电瓷, 1985(3): 2-8, 14. Yan Youliang, Ding Huazhong, Gou Yajiang.Research on improving the performance of oxygen-zinc resistors[J]. China Electric Ceramics, 1985(3): 2-8, 14. [51] 谭宜成, 刘子玉. ZnO阀片的制作新法及性能分析[J]. 电工技术学报, 1989, 4(1): 57-61. Tan Yicheng, Liu Ziyu.Analysis of the properties of ZnO varistors prepared by a new method[J]. Transa- ctions of China Electrotechnical Society, 1989, 4(1): 57-61. [52] 郭亚平, 史利民, 王建文, 等. 高压ZNO压敏电阻器制造技术研究(续)[J]. 电瓷避雷器, 1993(3): 35-42. Guo Yaping, Shi Limin, Wang Jianwen, et al.Research on manufacturing technology of high voltage ZNO varistor (continued)[J]. China Industrial Economics, 1993(3): 35-42. [53] 陈洪存, 陈玲, 肖鸣山. SiO2对ZnO压敏电阻器性能的影响[J]. 电子元件与材料, 1994, 13(4): 36-39. Chen Hongcun, Chen Ling, Xiao Mingshan.Effect of SiO2 on the performance of ZnO varistors[J]. Electronic Components $ Materials, 1994, 13(4): 36-39. [54] 陈廷吉, 何晓明. 提高ZnO电阻片性能的研究[J]. 电瓷避雷器, 1994(1): 34-38. Chen Tingji, He Xiaoming.Study on improving the performance of ZnO resistors[J]. Insulators and Surge Arresters, 1994(1): 34-38. [55] 韩述斌, 吴德喜, 范坤泰, 等. 掺杂TiO2对ZnO压敏电阻器的性能影响[J]. 传感器技术, 1996(3): 20-22. Han Shubin, Wu Dexi, Fan Kuntai, et al.The effect of doping TiO2 for ZnO varistors[J]. Journal of Trans- ducer Technology, 1996(3): 20-22. [56] Ezhilvalavan S, Kutty T R N. Effect of antimony oxide stoichiometry on the nonlinearity of zinc oxide varistor ceramics[J]. Materials Chemistry and Physics, 1997, 49(3): 258-269. [57] Bernik S, Daneu N.Characteristics of SnO2-doped ZnO-based varistor ceramics[J]. Journal of the European Ceramic Society, 2001, 21(10/11): 1879-1882. [58] 严群, 陈家钊, 涂铭旌. 添加Nd2O3对氧化锌压敏阀片电性能与显微组织的影响[J]. 硅酸盐学报, 2003, 31(12): 1179-1183. Yan Qun, Chen Jiazhao, Tu Mingjing.Influence of adding Nd2O3 on electrical properties and micro- structure of ZnO varistor ceramics[J]. Journal of the Chinese Ceramic Society, 2003, 31(12): 1179-1183. [59] 姚政, 翟维琴. 高电位梯度ZnO电阻片的研制[J]. 电瓷避雷器, 2003(3): 29-32. Yao Zheng, Zhai Weiqin.Development of MOA with high graduent[J]. Insulators and Surge Arresters, 2003(3): 29-32. [60] 李小鹏, 乐崐. ZnO非线性电阻片掺杂改性的研究[J]. 电瓷避雷器, 2004(4): 25-27, 31. Li Xiaopeng, Le Kun.Study on zinc oxide nonlinear resistor doped with rare-earth oxides[J]. Insulators and Surge Arresters, 2004(4): 25-27, 31. [61] 王玉平, 李盛涛. 新型ZnO压敏电阻片的研究进展[J]. 电气应用, 2005, 24(6): 1-2, 4, 6, 8, 21. Wang Yuping, Li Shengtao. Research progress of new ZnO varistor[J]. Electrotechnical Application, 2005, 24(6): 1-2, 4, 6, 8, 21. [62] 翟维琴, 姚政, 金继华, 等. 提高ZnO变阻器电性能的研究[J]. 功能材料, 2006, 37(11): 1758-1761, 1764. Zhai Weiqin, Yao Zheng, Jin Jihua, et al.Study on the improvement of the electric properties of ZnO varistors[J]. Journal of Functional Materials, 2006, 37(11): 1758-1761, 1764. [63] 黄彩清, 肖汉宁, 洪秀成, 等. 钇掺杂对ZnO电阻片微观结构和电性能的影响[J]. 电瓷避雷器, 2007(4): 24-27. Huang Caiqing, Xiao Hanning, Hong Xiucheng, et al.Microstructural and electrical characteristics of ZnO- Bi2O3-Sb2O3 based varistor ceramics doped with Y2O3[J]. Insulators and Surge Arresters, 2007(4): 24-27. [64] 李盛涛, 成鹏飞, 王玉平, 等. 稀土氧化物对ZnO- Bi2O3系压敏陶瓷晶粒分布及电气性能的影响[J]. 电瓷避雷器, 2008(5): 19-22. Li Shengtao, Cheng Pengfei, Wang Yuping, et al.Influence of rare-earth oxides on distribution of grain size and electrical properties of ZnO-Bi2O3 varistor ceramics[J]. Insulators and Surge Arresters, 2008(5): 19-22. [65] 徐东, 程晓农, 赵国平, 等. 复合稀土La和Sc掺杂氧化锌压敏瓷的显微组织和电性能[J]. 中南大学学报(自然科学版), 2010, 41(6): 2167-2172. Xu Dong, Cheng Xiaonong, Zhao Guoping, et al.Microstructure and electrical properties of lanthanum and scandium doped ZnO-Bi2O3-based varistor cera- mics[J]. Journal of Central South University, 2010, 41(6): 2167-2172. [66] 徐东, 史小锋, 程晓农. 氧化钪掺杂氧化锌压敏瓷的显微组织和电性能[J]. 电瓷避雷器, 2010(3): 23-26. Xu Dong, Shi Xiaofeng, Cheng Xiaonong.Micro- structure and electrical properties of Sc2O3-doped ZnO varistor ceramics[J]. Insulators and Surge Arresters, 2010(3): 23-26. [67] 王玉平, 成鹏飞. 直流ZnO电阻片的研究[J]. 电瓷避雷器, 2010(4): 34-37. Wang Yuping, Cheng Pengfei.Study on D.C.ZnO varistors[J]. Insulators and Surge Arresters, 2010(4): 34-37. [68] 黄国贤. 高电压梯度高通流能力氧化锌压敏电阻的研究[D]. 武汉: 华中科技大学, 2011. [69] 姚银华, 曹全喜, 邹青文. 四价添加剂掺杂ZnO压敏电阻器的性能[J]. 压电与声光, 2012, 34(6): 868-871, 876. Yao Yinhua, Cao Quanxi, Zou Qingwen.Performance of ZnO varistor with tetravalent additive[J]. Piezo- electrics & Acoustooptics, 2012, 34(6): 868-871, 876. [70] Bai Hairui, Li Shuhui, Zhao Yunhan, et al.Influence of Cr2O3 on highly nonlinear properties and low leakage current of ZnO-Bi2O3 varistor ceramics[J]. Ceramics International, 2016, 42(9): 10547-10550. [71] Zhao Hongfeng, He Jinliang, Hu Jun, et al.High nonlinearity and low residual-voltage ZnO varistor ceramics by synchronously doping Ga2O3 and Al2O3[J]. Materials Letters, 2016, 164: 80-83. [72] 孟鹏飞, 胡军, 邬锦波, 等. 采用镓离子掺杂的高通流容量氧化锌压敏电阻[J]. 中国电机工程学报, 2017, 37(24): 7377-7383. Meng Pengfei, Hu Jun, Wu Jinbo, et al.High impulse current discharge capability of ZnO varistors by doping gallium ions[J]. Proceedings of the CSEE, 2017, 37(24): 7377-7383. [73] 孟鹏飞, 胡军, 邬锦波, 等. 氧化锌压敏电阻综合性能的多元掺杂综合调控[J]. 高电压技术, 2018, 44(1): 241-247. Meng Pengfei, Hu Jun, Wu Jinbo, et al.Com- prehensive performances of ZnO varistors tailored by multi-elements doping[J]. High Voltage Engineering, 2018, 44(1): 241-247. [74] 万帅, 许衡, 席成圆, 等. Al、Ga离子对ZnO压敏电阻阀片电气性能的调控[J]. 高电压技术, 2020, 46(4): 1434-1440. Wan Shuai, Xu Heng, Xi Chengyuan, et al.Adju- stment of electrical properties of ZnO varistor ceramics by Co-doping with aluminum and gallium ions[J]. High Voltage Engineering, 2020, 46(4): 1434-1440. [75] 万帅, 许衡, 曹伟, 等. La2O3的掺杂对氧化锌压敏陶瓷电性能的影响[J]. 压电与声光, 2020, 42(3): 353-356, 360. Wan Shuai, Xu Heng, Cao Wei, et al.Effect of La2O3 doping on electrical properties of ZnO varistor ceramics[J]. Piezoelectrics & Acoustooptics, 2020, 42(3): 353-356, 360. [76] 程宽, 赵洪峰, 周远翔. 多元施主掺杂对直流ZnO压敏陶瓷结构与电气性能的影响[J]. 材料工程, 2022, 50(8): 153-159. Cheng Kuan, Zhao Hongfeng, Zhou Yuanxiang.Effect of multi-donor doping on structure and electrical properties of DC ZnO varistor ceramics[J]. Journal of Materials Engineering, 2022, 50(8): 153-159. [77] Imai T, Udagawa T, Ando H, et al.Development of high gradient zinc oxide nonlinear resistors and their application to surge arresters[J]. IEEE Transactions on Power Delivery, 1998, 13(4): 1182-1187. [78] Tsukamoto N, Ishii M.Repetitive impulse withstand performance of metal-oxide varistors[J]. IEEE Transa- ctions on Power Delivery, 2017, 32(4): 1674-1681. [79] 王玉平, 李盛涛, 孙西昌. ZnO压敏电阻片的应用研究进展[J]. 电气技术, 2006, 7(10): 17-24. Wang Yuping, Li Shengtao, Sun Xichang.Progress in development and application of ZnO varistors[J]. Electrical Engineering, 2006, 7(10): 17-24. [80] 何金良, 刘俊, 胡军, 等. 电力系统避雷器用ZnO压敏电阻研究进展[J]. 高电压技术, 2011, 37(3): 634-643. He Jinliang, Liu Jun, Hu Jun, et al.Development of ZnO varistors in metal oxide arrestors utilized in ultra high voltage systems[J]. High Voltage Engineering, 2011, 37(3): 634-643. [81] 李启厚, 吴希桃, 黄亚军, 等. 超细粉体材料表面包覆技术的研究现状[J]. 粉末冶金材料科学与工程, 2009, 14(1): 1-6. Li Qihou, Wu Xitao, Huang Yajun, et al.Status quo of study on surface coating technologies of ultra-fine powders[J]. Materials Science and Engineering of Powder Metallurgy, 2009, 14(1): 1-6. [82] 武七德, 王浩, 王萍. 表面包覆改性技术在陶瓷技术中的应用[J]. 现代技术陶瓷, 2000, 21(4): 18-21. Wu Qide, Wang Hao, Wang Ping.Application of modification technology on surface coating to ceramic process[J]. Advanced Ceramics, 2000, 21(4): 18-21. [83] 洪广言, 崔洪涛. 室温固相法用于材料表面包覆的研究[C]//全国室温固-固相化学反应研讨会论文集, 北京, 2003: 49-50. Hong Guangyan, Cui Hongtao.Research on surface coating of materials by solid-phase method at room temperature[C]//Proceeding of the National Sympo- sium on Solid-Solid Phase Chemical Reactions at Room Temperature, Beijing, 2003: 49-50. [84] 谢凤宽, 陈晓磊, 庄书娟, 等. 液相沉积法表面包覆改性纳米陶瓷微粒及机理研究进展[J]. 材料导报, 2006, 20(增刊1): 153-155, 158. Xie Fengkuan, Chen Xiaolei, Zhuang Shujuan, et al.Research progress in surface coating modification of nanoceramic particles by liquid deposition and their mechanisms[J]. Materials Review, 2006, 20(S1): 153-155, 158. [85] Zhang Huiliang, Cao Quanxi.ZnO varistor fabri- cated by Sol-gel method[J]. Instrument Technique and Sensor, 2007(8): 10-11, 40. [86] 张静. 锂硫电池材料的制备及其物理气相沉积法改性研究[D]. 合肥: 合肥工业大学, 2019. [87] 桑可正, 韩璐, 史文鹏, 等. Al2O3陶瓷表面化学气相沉积Ti涂层的研究[C]//第十一届全国工程陶瓷学术年会论文集, 2013: 129. Sang Kezheng, Han Lu, Shi Wenpeng, et al.Research on Ti coating on Al2O3 ceramic surface by chemical vapor deposition[C]//Proceedings of the 11th National Conference on Engineering Ceramics, 2013: 129-129. [88] Guan Y F, Pedraza A J.Synthesis and alignment of Zn and ZnO nanoparticles by laser-assisted chemical vapor deposition[J]. Nanotechnology, 2008, 19(4): 045609. [89] Pillai S C, Kelly J M, McCormack D E, et al. The effect of processing conditions on varistors prepared from nanocrystalline ZnO[J]. Journal of Materials Chemistry, 2003, 13(10): 2586-2590. [90] Yuan Fangli, Ryu H.Microstructure of varistors prepared with zinc oxide nanoparticles coated with Bi2O3[J]. Journal of the American Ceramic Society, 2004, 87(4): 736-738. [91] Li Yuke, Li Guorong, Yin Qingrui.Preparation of ZnO varistors by solution nano-coating technique[J]. Materials Science and Engineering: B, 2006, 130(1/2/3): 264-268. [92] 王琴, 秦勇, 段雷, 等. 溶液包裹法制备低压氧化锌压敏陶瓷[J]. 稀有金属材料与工程, 2007, 36(增刊2): 181-183. Wang Qin, Qin Yong, Duan Lei, et al.Low voltage ZnO varistor fabricated by solution-coating method[J]. Rare Metal Materials and Engineering, 2007, 36(S2): 181-183. [93] Ali Shojaee S, Maleki Shahraki M, Ali Faghihi Sani M, et al. Microstructural and electrical properties of varistors prepared from coated ZnO nanopowders[J]. Journal of Materials Science: Materials in Electronics, 2010, 21(6): 571-577. [94] Meng Lei, Zheng Liaoying, Cheng Lihong, et al.Synthesis of novel core-shell nanocomposites for fabricating high breakdown voltage ZnO varistors[J]. Journal of Materials Chemistry, 2011, 21(30): 11418-11423. [95] Wang Maohua, Zhou Fu, Zhang Bo.Synthesis of ZnO@Co2O3-Bi2O3-MnO core-shell structured nano- particles for varistors applications[J]. Powder Technology, 2014, 264: 514-518. [96] Liu Tingting, Wang Maohua, Zhang Hanping.Syn- thesis and characterization of ZnO/Bi2O3 core/shell nanoparticles by the Sol-gel method[J]. Journal of Electronic Materials, 2016, 45(8): 4412-4417. [97] Qu Xiao, Yao Dachuan, Liu Jinran, et al.Synthesis of SiO2-coated core-shell ZnO composites[J]. Journal of Electronic Materials, 2018, 47(1): 409-414. [98] 张海峰. ZnO掺杂及表面吸附的第一性原理研究[D]. 北京: 北京理工大学, 2015. [99] 王立惠. ZnO表界面及其相关特性的第一性原理研究[D]. 昆明: 昆明理工大学, 2009.