Zn electrode: Most reported aqueous ZIBs and Zn hybrid batteries directly use commercial Zn foil as the Zn anode. However, it suffers from several irreversibility issues during the
cycling process in mild aqueous electrolytes, such as the dendrite growth, corrosion, as well
as hydrogen evolution, which will affect the cycling performance of Zn-based systems. Until
now, only limited work focused on the optimization of Zn metal and the Zn electrode
reversibility behaviour under the aqueous mild electrolytes is not well understood. The
effective methods to suppress the dendrite growth and achieve high CE should be building a
stable artificial layer on Zn electrode surface and optimizing the electrolyte formulation.
Although the behaviour of Zn electrode in mild electrolytes is different with that in alkaline
electrolyte, knowledge accumulated in alkaline Zn batteries research to alleviate the dendrite
growth and side reactions can be applied to the investigation of AZIBs and aqueous Zn
hybrid batteries. Also, more progresses are desired to be achieved by learning from other
metal anode protecting technology such as Li/Na metal batteries. Moreover, the strategies for
improving the performance of Zn electrode should be demonstrated in full cells towards
practical applications.
Electrolyte: The optimization of the electrolyte are critical for achieving high performance batteries by enabling highly efficient Zn plating/stripping and stabilizing the cathode
materials, which are related to the Zn salts, salt concentrations, and additives. However,
development of the mild aqueous electrolytes in Zn-based battery systems is still a fresh
topic. Currently, most work adopted ZnSO4 or Zn(CF3SO3)2 as Zn salt for preparing the
aqueous electrolyte. However, batteries using ZnSO4 electrolyte still suffer from the rapid
capacity decay due to the formation and growth of Zn dendrites and electrode dissolution. In
addition, the formation and dissolution of hydroxide sulphate (Zn4(OH)6SO4·xH2O)
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electrochemical performance. Batteries employing the Zn(CF3SO3)2 electrolyte show
superior electrochemical properties compare to these using ZnSO4 electrolyte, the high price
of Zn(CF3SO3)2 severely retards its wide application on a large scale, however. Thus,
exploring the new Zn salts with affordable price will be worthwhile to unlock the potential of
Zn-based systems by enhancing the CE, cycling stability and rate performance, and more
importantly suppressing Zn dendrite growth. In addition, most of the aqueous Zn salt
electrolytes are actually the mild acidic electrolyte, where the issues of corrosion of the metal
and current collector should be considered and resolved. Moreover, the narrow
electrochemical window of aqueous electrolyte would trigger the water-based side reactions
and limit the operating voltage of cathode materials. Efforts are still highly desirable to
research the new additives or electrolyte concentration, aiming to expand the stability
window of electrolyte and bring more potential materials into Zn-based aqueous system.
Configuration: Currently, the vast majority of work about ZIBs and hybrid Zn batteries are still conducted in the coin cell or pouch cell. To meet the different demands at the future
market, the different types of aqueous Zn-based technologies should be available in parallel,
including coin cell, pouch cell, cylindrical cell (18650), and prismatic cell. An additional
challenge is whether strategies suitable for coin cells will work in large-scale cells, for
practical application, materials should be demonstrated in large-scale cells. In addition,
wearable and flexible electronics with high flexibility and reliable electrochemical properties
is a vibrant and active research area for the large demand of portable applications. Benefiting
from its green and sustainable features, flexible aqueous Zn-based devices may be a good
choice for practical wearable applications. However, only few works focused on flexible Zn-
based batteries in neutral or mild acidic media was proposed until now due to the limitations
of stable electrode materials and appropriate electrolyte. Therefore, new strategies are highly
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and outstanding flexibility for the further development of well-designed and safe Zn-based
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Appendix A: Publications
1. Junnan Hao, Bo Li, Xiaolong Li, Xiaohui Zeng, Shilin Zhang, Fuhua Yang, Sailin Liu,
Chao Wu, Zaiping Guo*. An in-depth study of Zn metal surface chemistry for advanced
aqueous Zn-ion batteries. Adv. Mater. (2020) 2003021
2. Junnan Hao, Fuhua Yang, Shilin Zhang, Hanna He, Guanglin Xia*, Yajie Liu,
Christophe Didier, Tongchao Liu, Wei Kong Pang, Vanessa K. Peterson, Jun Lu*,
Zaiping Guo*. Designing a Hybrid Electrode Towards High Energy Density with a
Staged Li+ and PF
6− De/intercalation Mechanism. Proc. Natl. Acad. Sci. U.S.A.
117 (2020) 2815–2823.
3. Junnan Hao, Xiaolong Li, Shilin Zhang, Fuhua Yang, Xiaohui Zeng, Xiaohui Zeng,
Shuai Zhang, Guyue Bo, Chunsheng Wang*, Zaiping Guo*. Designing dendrite-free zinc
anodes for advanced aqueous zinc batteries. Adv. Funct. Mater. (2020) 2001263.
4. Junnan Hao, Jian Zhang, Guanglin Xia, Yajie Liu, Yang Zheng, Wenchao Zhang,
Yongbing Tang*, Wei Kong Pang, Zaiping Guo*. Heterostructure Manipulation via in
Situ Localized Phase Transformation for High-Rate and Highly Durable Lithium Ion
Storage. ACS Nano 12 (2018) 10430–10438.
5. Junnan Hao, Jun Long, Bo Li, Xiaolong Li, Shilin Zhang, Fuhua Yang, Xiaohui Zeng,
Zhanhong Yang*, Wei Kong Pang, Zaiping Guo*. Toward High-Performance Hybrid
Zn-Based Batteries via Deeply Understanding Their Mechanism and Using Electrolyte
Additive. Adv. Funct. Mater. 29 (2019) 1903605.
6. Junnan Hao, Xiaolong Li, Xiaohe Song, Zaiping Guo*. Recent Progress and
Perspectives on Dual-Ion Batteries. EnergyChem 1 (2019) 100004.
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Zhou, Fan Zhang, Zhibo Li, Chun He*. Synthesis of three-dimensional N&S co-doped
rGO foam with high capacity and long cycling stability for supercapacitors. J. Colloid
Interface Sci. 537 (2019) 57–65.
8. Xiaolong Li#, Junnan Hao#, Rong Liu, Hanna He, Yuanming Wang, Gemeng Liang, Yang Liu, Guohui Yuan, Zaiping Guo*, Interfacing MXene Flakes on Fiber Fabric as an
Ultrafast Electron Transport Layer for High Performance Textile Electrodes. Energy
Storage Mater. In pressing.
9. Xiaohui Zeng#, Junnan Hao#, Zhijie Wang, Jianfeng Mao*, Zaiping Guo*. Recent
progress and perspectives on aqueous Zn-based rechargeable batteries with mild aqueous
electrolytes. Energy Storage Mater. 20 (2019) 410–437.
10. Shilin Zhang, Qining Fan, Ye Liu, Shibo Xi, Xiufan Liu, Zhibin Wu, Junnan Hao, Wei
Kong Pang, Tengfei Zhou*, Zaiping Guo*. Dehydration-triggered Ionic Channel
Engineering in Potassium Niobate for Li/K ion Storage. Adv. Mater. (2020) 2000380.
11. Fuhua Yang, Jian Hong, Junnan Hao, Shilin Zhang, Gemeng Liang, Jun Long, Yuqing
Liu, Nana Liu, Wei Kong Pang, Jun Chen, Zaiping Guo*.Ultrathin Few-Layer GeP
Nanosheets via Lithiation-Assisted Chemical Exfoliation and Their Application in
Sodium Storage. Adv. Energy Mater. 10 (2020) 1903826.
12. Shilin Zhang, Yang Zheng, Xuejuan Huang, Jian Hong, Bin Cao, Junnan Hao, Qining
Fan, Tengfei Zhou*, Zaiping Guo*.Structural Engineering of Hierarchical Micro-
nanostructured Ge-C Framework by Controlling the Nucleation for Ultralong-Life Li
Storage. Adv. Energy Mater. 9 (2019) 1900081.
13. Hanna He, Dan Huang, Qingmeng Gan, Junnan Hao, Sailin Liu, Zhibin Wu, Wei Kong
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Anion Vacancies Regulating Endows MoSSe with Fast and Stable Potassium Ion
Storage. ACS Nano 13 (2019) 11843–11852.
14. Fuhua Yang, Hong Gao, Junnan Hao, Shilin Zhang, Peng Li, Yuqing Liu, Jun Chen*,
Zaiping Guo*. Yolk-Shell Structured FeP@C Nanoboxes as Advanced Anode Materials
for Rechargeable Lithium-/Potassium-Ion Batteries. Adv. Funct. Mater. 29 (2019)
1808291.
15. Jun Long, Jinxing Gu, Zhanhong Yang*, Jianfeng Mao, Junnan Hao, Zhongfang Chen,
Zaiping Guo*. Highly porous, low band-gap NixMn3−xO4 (0.55 ≤ x ≤ 1.2) spinel
nanoparticles with in-situ coated carbon as advanced cathode materials for zinc-ion
batteries. J. Mater. Chem. A 7 (2019) 17854–17866.
16. Hong Gao, Fuhua Yang, Yang Zheng, Qing Zhang, Junnan Hao, Shilin Zhang, Hao
Zheng, Jun Chen*, Huakun Liu, Zaiping Guo*. Three-Dimensional Porous Cobalt
Phosphide Nanocubes Encapsulated in a Graphene Aerogel as an Advanced Anode with
High Coulombic Efficiency for High-Energy Lithium-Ion Batteries. ACS Appl. Mater.
Interfaces 11 (2019) 5373–5379.
17. Jing Cuan, Fan Zhang, Hongyu Zhang, Jun Long, Shilin Zhang, Gemeng Liang, Qili
Gao, Junnan Hao, Linxi Dong, Gaofeng Wang, Xuebin Yu. Heterostructure
Manipulation toward Ameliorating Electrodes for Better Lithium Storage Capability.
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Appendix B: Conferences & Activities
1. International Conference on Nanoscience and Nanotechnology, Wollongong, Australia,
Jan. 29th – Feb. 2nd, 2018
2. The 2019 International Symposium on Future Materials, North Wollongong, Australia,
Jan. 30th –Feb. 1st, 2019
3.2019 UOW-USTC Joint Research Workshop, North Wollongong, Australia, Aug. 19th – 21st, 2019
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Appendix C: Scholarships & Awards
1. 2018 ISEM Postgraduate Student Excellence Award
2. 2017 International Postgraduate Research Scholarships, Faculty of Engineering &
Information Sciences, University of Wollongong.