研究领域
1. Sustainable carbon nanomaterials
The nanostructures created by nature can be readily used as wonderful precursors for nanocarbons. That is what I learned in my postdoc research. Through combinations of various pre-treatments, carbonization steps, and chemical activations, we have succeeded in synthesizing a series of novel nature-inspired carbon nanomaterials in my postdoc research from various biomass sources, including hemp fibers, waste proteins, peat moss, and peanut shells . With optimized structures and compositions, these carbons exhibit excellent performance as electrodes for supercapacitors , ionic liquid EDLCs, LIB anodes and SIB anodes . This work has attracted great attention from both the research community and the public sector.
The fast-growing bioprocessing industry in Alberta provides us with valuable opportunities to use nanosized and pure cellulose and lignin as precursors. With impressive mechanical properties and excellent flexibility, nanocellulose is one of the most promising innovations in the modern forest industry. Depending on the processing, nanocellulose can be generally catalogued into 2 groups: cellulose nanofibrils (CNF) and nanocrystals (CNC). CNF are manufactured by mechanically delaminating or bacteria-assisted digesting cellulose rich biomass. They share similar geometric dimensions with CNTs, typically few micrometers in length and 10-50 nanometers in diameter. In the contrast, CNC, processed through acid digestion, is much shorter (~ 100 nm) and thinner (typically around 10 nm). Is it possible to carbonize and use them as low-cost substitute for CNTs? Our answer is YES for some applications in energy storage, especially for composite electrode. The functionality-rich surface of nanocellulose plays a key role.
2. Understanding the stress in rechargeable batteries for better cycle-life
Stress in the charge/discharge remains the most likely culprit for electrode degradation and capacity fading in batteries. Unfortunately, we have very limited understanding of stress itself and therefore no specified solution. Although the in situ microscopy and spectrometry provide valuable insights into the impacts of the stress buildup and release (e.g., the stress-induced structure changes), the strength of stress is poorly understood, which is a knowledge gap in understanding the charge storage mechanism.
Emerged from atomic force microscopy (AFM), microcantilever sensors are freestanding beams with extremely high sensitivity to stress. Inspired by the ultrahigh sensitivity of microcantilevers, we have developed a cantilever-based platform and quantitively analyzed the localized stress induced in few-layers MoS2 upon the intercalation and extraction of Na. These results can be readily adapted to resolve the stress in a wide-range of electrode materials, gain additional insights into mechanical effects of charge storage, and for long life time battery design.
3. Sustainable filter to remove the PM 2.5
Particle pollution, also called particulate matter (PM), is a mixture of solids and liquid droplets floating in the air. According to the size of particles, pollutant can be cataloged into 3 groups: coarse particles (PM 10, <10µm), (PM 2.5, <2.5µm) and ultrafine particles (UFPs, <1.0 or even 0.1 µm). Compared to PM10 and PM 2.5, UFPs do much more damage to human body because of their small size: i) UFPs can evade human phagocytosis system and deposited in the lung with a high rate of retention; ii) UFPs deposited in the lung can translocate to other organs through the circulation; iii) UFPs can even penetrate intracellularly and lead to potential DNA damage; iv) with the high specific surface area, UFPs carry much more adsorbed hazardous chemicals.
In the heavily polluted regions especially in developing countries like India and China, low-cost, and efficient personal respiratory protection devices are essential for public health. The traditional cotton surgical face mask may help with the PM 10 but become futile with PM 2.5.
We built a homemade automatic respiratory system which mimics the continuous human breathing. This system allows us to accurately evaluate the PM 2.5 removal efficiency and life time of filtration media. We are having fun in developing low-cost filtration media based on sustainable nanomaterials.
近期论文
查看导师最新文章
(温馨提示:请注意重名现象,建议点开原文通过作者单位确认)
Li, Z.*.; Jiang, K.; Khan, F.; Goswami, A.; Liu, J.; Passian, A.; Thundat, T.*, Anomalous interfacial stress generation during sodium intercalation/extraction in MoS2 thin film anodes. Sci. Adv. 2019, 5 (1), eaav2820.
Xu, Z*.; Yao, K.; Fu, H.; Yao, K.; Shen, X.; Li, Z.*; Fu, L.; Huang, J.*; Li, J., Elemental Sulfur Nanoparticles Chemically Boost the Sodium Storage Performance of MoS2/rGO Anodes. Batteries & Supercaps 2018, doi: 10.1002/batt.201800060
Xu, Z*.; Yao, K.; Li, Z.; Fu, L.; Fu, H.; Li, J.; Cao, L.; Huang, J.*, Sulfur nanodots as MoS2 antiblocking agent for stable sodium ion battery anodes. J. Mater. Chem. A 2018, 6 (22), 10535-10542.
Yao, K.; Xu, Z.*; Li, Z.; Liu, X.; Shen, X.; Cao, L.; Huang, J.*, Synthesis of Grain-like MoS2 for High-Performance Sodium-Ion Batteries. ChemSusChem 2018, 11 (13), 2130-2137.
Liu, J.*; Miao, M.; Jiang, K.; Khan, F.; Goswami, A.; McGee, R.; Li, Z.; Nguyen, L.; Hu, Z.; Lee, J.; Cadien, K.; Thundat, T*., Sustained electron tunneling at unbiased metal-insulator-semiconductor triboelectric contacts. Nano Energy 2018, 48, 320-326.
Liu, J.*; Goswami, A.; Jiang, K.; Khan, F.; Kim, M.; McGee, R. T.; Li, Z.; Hu, Z.; Lee, J.; Thundat, T.*, Direct-current triboelectricity generation by sliding-Schottky nanocontact on MoS2 multilayers, Nat. Nanotechnol. 2018, 13, 112
Li, Z.*; Ahadil, K.; Jiang, K.; Ahvazi, B.; Li, P.; Anyia, A. O.; Cadien, K.; Thundat, T.*, Free-standing hierarchical porous carbon Film derived from hybrid nanocellulose for high power supercapacitors, Nano Res., 2017, 10(5), 1847-1860.
Ding, J.*; Zhou, H.; Zhang, H.; Stephenson, T.; Li, Z.; Karpuzov, D.; Mitlin, D*. Exceptional Energy and New Insight with a Sodium–Selenium Battery Based on a Carbon Nanosheet Cathode and a Pseudographite Anode. Energy Environ. Sci. 2017, 10, 153-165.
Li, Z.*; Liu, J.; Jiang, K. R.; Thundat, T.*, Carbonized Nanocellulose Sustainably Boosts the Performance of Activated Carbon in Ionic Liquid Supercapacitors, Nano Energy, 2016, 25, 161-169.
Wang, H.; Mitlin, D.*; Ding, J.; Li, Z.*; Cui, K., Excellent energy–power characteristics from a hybrid sodium ion capacitor based on identical carbon nanosheets in both electrodes. J. Mater. Chem. A 2016, 4, 5149-5158.
Ding, J.*; Li, Z.; Cui, K.; Boyer, S.; Karpuzov, D.; Mitlin, D.*, Heteroatom Enhanced sodium Ion capacity and rate capability in a hydrogel derived carbon give record performance in a hybrid Ion capacitor, Nano Energy, 2016, 23, 129–137.
Liu, J.*; Prashanthi, K.; Li, Z.; McGee, R. T.; Ahadi, K.; Thundat, T.*, Strain-Induced Electrostatic Enhancements of Bifeo 3 Nanowire Loops, Phys. Chem. Chem. Phys. 2016, 18, 22772-22777.
Li, Z.; Ding, J.; Mitlin, D.*, Tin and Tin Compounds for Sodium Ion Battery Anodes: Phase Transformations and Performance, Acc. Chem. Res. 2015, 48(6), 1657-1665. ‘ESI Highly Cited Paper’
Li, Z.*; Tan, X. H.; Li, P.; Kalisvaart, W. P.; Mook, W. M.; Luber, E.; Jungjohann, K.; Cater, B.; Mitlin, D., Coupling in situ and ex situ analysis to understand the heterogeneous sodiation of Sb, Nano Lett., 2015, 15(10), 6339-6348
Li, Z.; Ding, J.; Wang, H.*; Cui, K.; Stephenson, T.; Karpuzov, D.; Mitlin, D.*, High Rate SnO2 - Graphene Dual Aerogel Anodes and the Kinetics of Lithiation versus Sodiation, Nano Energy, 2015, 15, 369-378.
Ding, J.; Wang, H.; Li, Z.*; Cui, K.; Karpuzov, D.; Xu, Z.; Tan, X.; Kohandehghan, A.; Mitlin, D.*, Peanut shell hybrid sodium ion capacitor with extreme energy - power rivals lithium ion capacitors, Energy Environ. Sci., 2015, 8 (3), 941-955. ‘ESI Highly Cited Paper’
Ding, J.*; Li, Z.; Wang, H.; Cui, K.; Kohandehghan, A.; Tan, X.; Karpuzov, D.; Mitlin, D.*, Sodiation vs. Lithiation Phase Transformations in a High Rate - High Stability SnO2 in Carbon Nanocomposite. J. Mater. Chem. A 2015, 3, 7100.
Tan, X.*; Wang, L.; Zahiri, B.; Kohandehghan, A.; Karpuzov, D.; Lotfabad, E. M.; Li, Z.; Eikerling, M. H.; Mitlin, D.*, Titanium Oxynitride Interlayer to Influence Oxygen Reduction Reaction Activity and Corrosion Stability of Pt and Pt–Ni Alloy. ChemSusChem 2015, 8, 361-376.
Li, Z.; Xu, Z.; Wang, H.*; Ding, J.; Zahiri, B.; Holt, C. M. B.; Tan, X.; Mitlin, D.*, Colossal pseudocapacitance in a high functionality - high surface area carbon anode doubles the energy of an asymmetric supercapacitor, Energy Environ. Sci. 2014, 7(5), 1708-1718. ‘ESI Highly Cited Paper’
Li, Z.; Ji, Y.; Cadigan, C.; Richards, R.M.*, Thermally stable gold/alumina aerogel catalysts prepared by a simultaneous synthesis process for solvent-free aerobic benzyl alcohol oxidation, RSC Catal. Sci. Tech. 2014, 4, 2520-2525.