Zhihui Wang

US Patent:

20190013513, Jan 10, 2019

Filed:

Jan 4, 2017

Appl. No.:

16/067795

Inventors:

- Santa Clara CA, US
Sergey D. LOPATIN - Morgan Hill CA, US
Eric H. LIU - Los Altos CA, US
Ajey M. JOSHI - San Jose CA, US
Guo AI - Guangdong, CN
Zhihui WANG - Fremont CA, US
Hui ZHAO - Boston MA, US
Donghai WANG - State College PA, US

International Classification:

H01M 4/139
H01M 4/62
H01M 4/04
H01M 4/38
H01M 4/587
H01M 4/36
H01M 4/48
H01M 10/0525

Abstract:

A simple solution processing method is developed to achieve uniform and scalable stabilized lithium metal powder coating on Li-ion negative electrode. A solvent and binder system for stabilized lithium metal powder coating is developed, including the selection of solvent, polymer binder and enhancement of polymer concentration. The enhanced binder solution is 1% concentration of polymer binder in xylene, and the polymer binder is chosen as the mixture of poly(styrene-co-butadiene) rubber (SBR) and polystyrene (PS). Long-sustained, uniformly dispersed stabilized lithium metal powder suspension can be achieved with the enhanced binder solution. A uniform stabilized lithium metal powder coating can be achieved with simple doctor blade coating method and the resulting stabilized lithium metal powder coating can firmly glued on the anode surface. With the prelithiation of negative electrode by stabilized lithium metal powder, improvements in electrochemical performances are demonstrated in both graphite/NMC and SiO/NMC full-cell.

US Patent:

20160315313, Oct 27, 2016

Filed:

Apr 22, 2015

Appl. No.:

14/693177

Inventors:

- Menlo Park CA, US
Yuki Matsuoka - Menlo Park CA, US
Zhihui Wang - Menlo Park CA, US

International Classification:

H01M 4/36
C25D 5/10
C25D 15/00
H01M 4/134
H01M 4/587
H01M 4/38
H01M 10/0525
H01M 4/133

Abstract:

In forming an anode by using metallic lithium as the anode active material, the present invention provides an anode for lithium batteries which can be produced with high productivity and in which dendrite generation is prevented, so that high safety can be secured. The anode for lithium batteries according to the present invention comprises a structure, comprising a conductive material layer in which carbon nanotubes are anchored, with a part of the carbon nanotube extending from at least one face of the surfaces of the conductive material layer, and a deposited layer formed by depositing metallic lithium on the carbon nanotubes in the structure.

US Patent:

20150364755, Dec 17, 2015

Filed:

Jun 16, 2015

Appl. No.:

14/741350

Inventors:

Gao Liu - Piedmont CA, US
Hui Zhao - Emeryville CA, US
Zhihui Wang - Fremont CA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

H01M 4/36
H01M 4/38
H01M 4/04
H01M 4/583
H01M 4/66
H01M 4/62
H01B 1/12
H01M 4/48

Abstract:

Silicon alloys have the highest specific capacity when used as anode material for lithium-ion batteries, however, the drastic volume change inherent in their use causes formidable challenges toward achieving stable cycling performance. Large quantities of binders and conductive additives are typically necessary to maintain good cell performance. In one embodiment of the invention, only 2% (by weight) functional conductive polymer binder without any conductive additives was successfully used with a micron-size silicon monoxide (SiO) anode material, demonstrating stable and high gravimetric capacity (>1000 mAh/g) for 500 cycles and more than 90% capacity retention. Prelithiation of this anode using stabilized lithium metal powder (SLMP) improves the first cycle Coulombic efficiency of a SiO/NMC full cell from 48% to 90%. This combination enables good capacity retention of more than 80% after 100 cycles at C/3 in a lithium-ion full cell.

US Patent:

20150144013, May 28, 2015

Filed:

Nov 21, 2014

Appl. No.:

14/550766

Inventors:

Gao Liu - Piedmont CA, US
Vince Battaglia - San Anselmo CA, US
Zhihui Wang - Fremont CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H01M 4/04

US Classification:

100102

Abstract:

An embodiment of the invention describes an calendaring apparatus comprising a roller press comprising a first roller and a second roller, a static electricity generator, a motor drive system in communication with the first roller and the second roller to impart rotation to first roller and the second roller, wherein the static electricity generator imparts a static charge to a surface of the first roller, and a material holding tray for holding a material in communication with the first roller.