# Enyuan Hu
**Enyuan Hu** is a battery chemist and principal investigator in the Electrochemical Energy Storage Group of the Chemistry Division at [Brookhaven National Laboratory](https://www.edgepedia.org/brookhaven-national-laboratory) (BNL) in Upton, New York, where his team works on lithium metal, lithium sulfur, and solid-state batteries.[1](https://www.bnl.gov/staff/enhu) He applies synchrotron x-ray and neutron scattering methods to the interphases that form on electrodes during cycling and to the oxygen redox reaction in battery cathode materials.[1](https://www.bnl.gov/staff/enhu)
| Key fact | Detail |
|---|---|
| Position | Chemist, Chemistry Division, Brookhaven National Laboratory (since 2023); PI of the Electrochemical Energy Storage Group[1](https://www.bnl.gov/staff/enhu) |
| Education | Ph.D. Mechanical Engineering, Stony Brook University (2009–2015); M.S. Guangzhou Institute of Energy Conversion (2005–2008); B.E. Southeast University (2001–2005)[1](https://www.bnl.gov/staff/enhu) |
| Signature work | "Evolution of redox couples in Li- and Mn-rich cathode materials and mitigation of voltage fade by reducing oxygen release", *Nature Energy*, 2018[2](https://www.osti.gov/servlets/purl/1460715) |
| Methods | Synchrotron x-ray total scattering for interphases; operando neutron diffraction for cathode oxygen redox; NSLS-II beamlines including XPD[1](https://www.bnl.gov/staff/enhu) • [3](https://www.sciencedaily.com/releases/2024/01/240126140526.htm) |
| Awards | IBA Early Career Award (2023); Materials Today Rising Star Award 2025[1](https://www.bnl.gov/staff/enhu) |
| Other roles | Adjunct professor, Department of Materials Science and Chemical Engineering, Stony Brook University; associate editor of *Nano Energy*[1](https://www.bnl.gov/staff/enhu) |
## Education and career
Hu earned a B.E. in Environmental Engineering from [Southeast University](https://www.edgepedia.org/southeast-university), China (2001–2005), an M.S. in Environmental Engineering from the Guangzhou Institute of Energy Conversion, China (2005–2008), and a Ph.D. in Mechanical Engineering from [Stony Brook University](https://www.edgepedia.org/stony-brook-university) (2009–2015).[1](https://www.bnl.gov/staff/enhu)
His Brookhaven career progressed through dated ranks: Research Associate 2015–2018, Assistant Chemist 2018–2020, Associate Chemist 2020–2023, and Chemist from 2023.[1](https://www.bnl.gov/staff/enhu) He also holds an adjunct professorship in the Department of Materials Science and Chemical Engineering at Stony Brook University and became an associate editor for *Nano Energy*.[1](https://www.bnl.gov/staff/enhu)
## Research
The interphase is a solid thin layer that forms on the battery's cathode during cycling. Hu pioneered the use of synchrotron x-ray total scattering to characterize these interphases and of neutron total scattering to study the oxygen redox reaction in cathode materials.[1](https://www.bnl.gov/staff/enhu) His group has characterized more than 1,000 interphase samples at NSLS-II's XPD beamline without observing radiation damage, drawing on more than five years of work at that beamline.[3](https://www.sciencedaily.com/releases/2024/01/240126140526.htm)
A 2016 *Nano Letters* study on prelithiated Li2Ru0.5Mn0.5O3, using x-ray diffraction, pair distribution function analysis, x-ray absorption spectroscopy, and aberration-corrected scanning transmission electron microscopy, showed that nano-sized grain boundaries and oxygen release form a positive feedback loop during cycling, accelerating the two major contributors to voltage fade: transition metal reduction and the layered-to-spinel phase transition.[4](https://doi.org/10.1021/acs.nanolett.6b01609)
His electrolyte work uses several NSLS-II beamlines in parallel: QAS to track transition-metal dissolution, SRX to map metal deposition on the anode, IOS for cathode-surface characterization, and XPD for crystal-structure changes over cycles.[5](https://www.bnl.gov/newsroom/news.php?a=119584)
## Representative work
The 2018 *Nature Energy* paper "Evolution of redox couples in Li- and Mn-rich cathode materials and mitigation of voltage fade by reducing oxygen release" explained why lithium- and manganese-rich layered cathodes lose voltage as they cycle. Using in situ and ex situ multi-length-scale x-ray spectroscopy and 3D electron microscopy on Li1.2Ni0.15Co0.1Mn0.55O2, the study showed that oxygen release continuously reduces the average valence states of the transition-metal cations, activating the lower-voltage Mn3+/Mn4+ and Co2+/Co3+ redox couples alongside the original Ni and oxygen couples, which directly causes voltage fade; oxygen release also creates microstructural defects such as large pores within particles, and surface coating and modification were proposed as mitigation.[2](https://www.osti.gov/servlets/purl/1460715)
## Additive engineering and high-voltage cathodes
Hu's group stabilizes nickel-rich layered cathodes by engineering the electrolyte rather than the cathode itself. A Brookhaven news release reported that an electrolyte additive enabled a nickel-rich layered cathode to cycle at high voltages while retaining 97 percent of its initial capacity after 200 cycles.[5](https://www.bnl.gov/newsroom/news.php?a=119584) As the additive decomposes it produces lithium phosphate (Li3PO4) and lithium fluoride (LiF), forming a protective cathode-electrolyte interphase that suppresses transition metal dissolution from the cathode and its subsequent deposition on the anode, a failure mode the battery community calls "crosstalk".[5](https://www.bnl.gov/newsroom/news.php?a=119584) In January 2024 the group reported a cesium nitrate additive for fast-charging batteries, again characterized at four NSLS-II beamlines including XPD.[3](https://www.sciencedaily.com/releases/2024/01/240126140526.htm)
## Anionic redox in nickel-rich cathodes
Anionic redox means the direct oxidation of lattice oxygen ions during charging, in addition to the oxidation of transition-metal cations. A 2021 *Energy & Environmental Science* paper used high-throughput operando neutron diffraction to reveal a universal four-stage structural evolution of Ni-rich cathodes during the initial cycle, and discovered a structural transition at about 75% delithiation, independent of nickel or substituent content, hallmarked by an anomalous increase of average transition-metal–oxygen bond lengths during charge, the opposite of the shortening expected on oxidation.[6](https://www.osti.gov/pages/servlets/purl/1827176) The anomaly is induced by direct oxidation of lattice oxygen ions, rooted in a drastic decrease of the oxygen-to-transition-metal charge transfer gap at high degrees of delithiation.[6](https://www.osti.gov/pages/servlets/purl/1827176) The onset of this anomaly matches the onset of oxygen gas release and severe capacity-retention decline, indicating a key role in Ni-rich cathode degradation.[6](https://www.osti.gov/pages/servlets/purl/1827176)
## Awards and recognition
Hu received the International Battery Material Association (IBA) Early Career Award in 2023.[1](https://www.bnl.gov/staff/enhu) He also received the Materials Today Rising Star Award 2025 in Energy Conversion & Storage.[1](https://www.bnl.gov/staff/enhu)
## Recent directions
In 2024 he co-authored papers in *JACS* on synergistic anion and solvent-derived interphases for lithium-ion batteries under extreme conditions and on lithium metal interphase components, and co-authored "Ligand-channel-enabled ultrafast Li-ion conduction" in *Nature* 627:101–107.[1](https://www.bnl.gov/staff/enhu) In 2025 he co-authored a *Chemical Reviews* review (125:9834–9874) on x-ray diffraction studies of single-crystal materials for battery applications, and in 2026 his group published "Revealing key structures for reversible sulfur redox in amorphous polymeric sulfur" in *Nature Materials*.[1](https://www.bnl.gov/staff/enhu)
## References
1. [BNL | Staff | Enyuan Hu, Chemistry Division](https://www.bnl.gov/staff/enhu)
2. [Evolution of redox couples in Li- and Mn-rich cathode materials and mitigation of voltage fade by reducing oxygen release (OSTI full text)](https://www.osti.gov/servlets/purl/1460715)
3. [Engineered battery chemistry for fast charging capabilities (ScienceDaily)](https://www.sciencedaily.com/releases/2024/01/240126140526.htm)
4. [Explore the Effects of Microstructural Defects on Voltage Fade of Li- and Mn-Rich Cathodes (Nano Letters)](https://doi.org/10.1021/acs.nanolett.6b01609)
5. [Electrolyte Additive Offers Lithium Battery Performance Breakthrough | BNL Newsroom](https://www.bnl.gov/newsroom/news.php?a=119584)
6. [Anionic Redox Induced Anomalous Structural Transition in Ni-rich Cathodes (OSTI full text)](https://www.osti.gov/pages/servlets/purl/1827176)
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*Topic: Encyclopedia › Technology and the built world › Engineers and computer scientists › Engineers and materials scientists › Researchers in chemical engineering, batteries, solar, and energy materials › Lithium-ion and solid-state batteries*
*Initially written Sep 21, 2026 · Edited: Oct 15, 2026*
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License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license