Yuzhang (Shawn) Li

Hi! I am a materials science PhD student working with professor Yi Cui at Stanford. My research interests are in the design and characterization of high-energy battery materials. Contact me here for further discussion.
[CV] - ver. 12/2016

University of California, Berkeley
Chemical Engineering, B.S.
High Honors, 2013

Stanford University
Materials Science & Engineering, Ph.D.
In Progress 2013-

Lithium-ion batteries
Current research at Stanford University

High-energy lithium battery chemistries (e.g. silicon, lithium metal, sulfur) have the potential to facilitate our transition away from fossil fuels and towards renewable energy resources (solar, wind). In particular, silicon has more than ten times the capacity of conventional battery materials. Unfortunately, batteries using silicon cannot be recharged because the material fractures and loses electrical contact during charging and discharging, rendering the broken particles inactive. For the first time, we’ve demonstrated that by encapsulating each silicon particle within a graphene cage, the ruptured fragments continue to be electrochemically active. This graphene cage encapsulation strategy (patent submitted) allows us to achieve specific capacities more than four times that of conventional materials and enable the stabilized silicon to be recharged 300 times.
Graphene cage encapsulated silicon

When used in lithium-ion battery anodes, silicon microparticles swell, break apart and react with the battery’s electrolyte to form a thick coating that saps the anode's performance, top. To address these problems, we built a graphene cage around each particle, bottom. The cage gives the particle room to swell during charging, holds its pieces together when it breaks apart, controls the growth of the coating and preserves electrical conductivity and performance. (Y. Li et al., Nature Energy)

In situ TEM lithiation

This time-lapse movie from an electron microscope shows the new battery material in action: a silicon particle expanding and cracking inside a graphene cage while being charged. The cage holds the pieces of the particle together and preserves its electrical conductivity and performance. (H. Lee, Y. Li/Stanford University)

Dry eye disease
Previous research at UC Berkeley

Dry eye disease is one of the most common human ocular disorders, affecting up to 60% of the world’s population and characterized by a painful burning and itching sensation. Contact lens wear and dry climates further exacerbate these symptoms. A primary cause of this disease is excessive evaporation of tears, which greatly increases the salinity in our eyes. Thus, studying rates of human tear evaporation is key to understanding and possibly alleviating dry eye disease. Previously, devices for measuring tear evaporation were flawed in their design and unable to account for several important experimental variables (i.e. air flow, temperature, and humidity). Considering the fundamental mass and energy concepts for the evaporation of water, we designed an accurate, safe, and convenient diagnostic tool for clinical evaluation of dry-eye related maladies (patent submitted).
Berkeley flow evaporimeter design

Schematic of proposed flow evaporimeter attached to a goggle. At a set flow volumetric rate, Q, inlet and exit relative humidities, RH, and temperatures, T, are measured permitting calculation of evaporation rate. Dimensions are in centimeters. Drawing is not drawn to scale.

  1. Y. Sun, Y. Li, J. Sun, Y. Li, A. Pei, and Y. Cui.
    "Stabilized Li3N for efficient battery cathode prelithiation."
    Energy Storage Materials 6 (2017): 119-124

  2. W. Chen, Y. Liu, Y. Li, J. Sun, Y. Qiu, C. Liu, G. Zhou, and Y. Cui.
    "In Situ Electrochemically Derived Nanoporous Oxides from Transition Metal Dichalcogenides for Active Oxygen Evolution Catalysts."
    Nano Letters (2016)

  3. H. Wang, S. Xu, C. Tsai, Y. Li, C. Liu, J. Zhao, Y. Liu, H. Yuan, F. Abild-Pedersen, F.B. Prinz, J.K. Nørskov, and Y. Cui.
    "Direct and continuous strain control of catalysts with tunable battery electrode materials."
    Science 354.6315 (2016): 1031-1036

  4. J. Sun, Y. Sun, M. Pasta, G. Zhou, Y. Li, W. Liu, F. Xiong, and Y. Cui.
    "Entrapment of Polysulfides by a Black-Phosphorus-Modified Separator for Lithium-Sulfur Batteries."
    Advanced Materials 28.44 (2016): 9797-9803

  5. H.W. Lee, Y. Li, and Y. Cui.
    "Perspectives in in situ transmission electron microscopy studies on lithium battery electrodes."
    Current Opinion in Chemical Engineering 12 (2016): 37-43

  6. K. Yan, Z. Lu, H.W. Lee, F. Xiong, P.C. Hsu, Y. Li, J. Zhao, S. Chu, and Y. Cui.
    "Selective deposition and stable encapsulation of lithium through heterogeneous seeded growth."
    Nature Energy 1 (2016): 16010

  7. Y. Li*, K. Yan*, H.W. Lee, Z. Lu, N. Liu, and Y. Cui.
    "Growth of conformal graphene cages on micrometre-sized silicon particles as stable battery anodes."
    Nature Energy 1 (2016): 15029.

  8. Y. Sun, H.W. Lee, Z.W. Seh, N. Liu, J. Sun, Y. Li, and Y. Cui.
    "High-capacity battery cathode prelithiation to offset initial lithium loss."
    Nature Energy 1 (2016): 15008.

  9. Z. Chen, P.C. Hsu, J. Lopez, Y. Li, J. To, N. Liu, C. Wang, S. Andrews, Y. Cui, and Z. Bao.
    "Fast and reversible thermoresponsive polymer switching materials for safer batteries."
    Nature Energy 1 (2016): 15009.

  10. J. Sun*, H.W. Lee*, M. Pasta, H. Yuan, G. Zheng, Y. Sun, Y. Li, and Y. Cui.
    "A phosphorene-graphene hybrid material as a high-capacity anode for sodium-ion batteries."
    Nature Nanotechnology 10.11 (2015): 980-985.

  11. W. Chen, H. Wang, Y. Li, Y. Liu, J. Sun, S. Lee, J.S. Lee, and Y. Cui.
    "In Situ Electrochemical Oxidation Tuning of Transition Metal Disulfides to Oxides for Enhanced Water Oxidation."
    ACS Central Science 1.5 (2015): 244-251.

  12. W. Liu, N. Liu, J. Sun, P.C. Hsu, Y. Li, H.W. Lee, and Y. Cui.
    "Ionic Conductivity Enhancement of Polymer Electrolytes with Ceramic Nanowire Fillers."
    Nano Letters 15.4 (2015): 2740-2745.

  13. Z. Lu, N. Liu, H.W. Lee, J. Zhao, W. Li, Y. Li, and Y. Cui.
    "Nonfilling Carbon Coating of Porous Silicon Micrometer-Sized Particles for High-Performance Lithium Battery Anodes."
    ACS Nano 9.3 (2015): 2540-2547.

  14. C. Peng, C. Cerretani, Y. Li, S. Bowers, S. Shahsavarani, M. Lin, and C.J. Radke.
    "Flow Evaporimeter To Assess Evaporative Resistance of Human Tear-Film Lipid Layer."
    Industrial & Engineering Chemistry Research 53.47 (2014): 18130-18139.

  15. J. Sandler, Y. Li, R.N. Horne, and K. Li.
    "Effects of Fracture and Frequency on Resistivity in Different Rocks."
    EUROPEC/EAGE Conference and Exhibition. Society of Petroleum Engineers, 2009.

For platinum catalysts, a tiny squeeze gives a big boost in performance
Mark Shwartz, Stanford Precourt Insitute for Energy, 24 November 2016

A nanosize squeeze can significantly boost the performance of platinum catalysts that help generate energy in fuel cells, according to a new study by Stanford scientists. The team bonded a platinum catalyst to a thin material that expands and contracts as electrons move in and out, and found that squeezing the platinum a fraction of a nanometer nearly doubled its catalytic activity...Read more
LCOPt image

Batteries: Bigger and better
Thomas Fuller, News and Views (Nature Energy), 05 February 2016

Micrometre-sized silicon particles are attractive negative-electrode materials for lithium-ion batteries but are prone to mechanical failure during electrochemical cycling. Now, graphene cages grown conformally around the micro-silicon particles are shown to improve their cycling stability...Read more

Putting Silicon ‘Sawdust’ in a Graphene Cage Boosts Battery Performance
Glennda Chui, Press Release (SLAC National Accelerator Laboratory), 28 January 2016

Approach could remove major obstacles to increasing the capacity of lithium-ion batteries ...Read more
SLAC image

Cheap plastic film prevents batteries from catching fire
Robert Service, Latest News (Science Magazine), 11 January 2016

A network of spiky nickel nanoparticles allows electrical current to conduct through a battery, and shuts it down if the battery overheats...Read more
SpikyNi image

New fuel-cell materials could pave the way for practical hydrogen-powered cars
Precourt Institute for Energy, Stanford Energy News, 15 July 2015

Hydrogen fuel cells promise clean cars that emit only water. Several major car manufacturers have recently announced their investment to increase the availability of fueling stations while others are currently rolling out new models and prototypes. However, challenges remain, including the chemistry to produce and use hydrogen and oxygen gas efficiently...Read more

In Situ electrochemical tuning image