research statement 2014-2015

1. Research statement
Toru Hara, PhD
2014 - 2015
1. Proof of concept on flow-assist-free Zn/NiOOH battery (granted by the World Bank and
the Government of the Republic of Kazakhstan)
January 2015 to August 2015
As the inventor, the initiator, and the Co-Principal Investigator.
- Patents = 1 Kazakhstan Patent, 1 PCT, 1 US Patent, 1 Chinese patent, 1 European patent,
applied.
- Publications = 1 conference paper.
- Supervision = 1 postdoctoral researcher, 4 MBA candidates, 2 master's degree holders, 2
bachelor's degree holders.
- The uniqueness (novelty) of the flow-assist-free Zn/NiOOH battery is realized in combination:
(1) a carbon-based porous current collector such as polyacrylonitrile-based carbon fiber paper or
felt having an electrodeposited anode material, zinc, thereon, thereby forming a porous anode;
(2) an electropolymerized Zn whisker growth suppressor conformally coated onto the Zn anode;
(3) a carbon-based porous current collector such as polyacrylonitrile-based carbon fiber paper or
felt having an electrodeposited cathode material, NiOOH, thereon, thereby forming a porous
cathode; and (4) a separator and an aqueous (water-based) electrolyte solution such as KOH
solution.
Renewable energy integration into electrical grids is crucial for energy security, leading to the
highly secured communication network, traffic control, industrial activities, etc. However,
renewable energies are intermittent and cannot be directly integrated to electric grids without
using batteries. These batteries must be safe and inexpensive from the viewpoint of life-cycle-
cost. Aqueous batteries are non-flammable that can be a great merit compared with traditional
lithium-ion batteries that use flammable organic electrolyte solutions.
Among various types of aqueous rechargeable batteries, Zn/NiOOH system is a promising
candidate: it does not use toxic materials unlike lead-acid batteries; it uses the Zn anode that
delivers a higher gravimetric capacity (818 mAh g-1) than metal hydride (e.g.,
LaNi3.55Co0.75Mn0.4Al0.3, 300 mAh g-1 or less) and a comparable potential (-0.76 V vs. Standard
Hydrogen Electrode, SHE) in aqueous media with metal hydride (e.g., LaNi3.55Co0.75Mn0.4Al0.3, -
0.75 to -0.85 V vs. SHE). The problem is Zn dendrite formation resulting in internal short circuit
failure. NiOOH can deliver 292 - 467 mAh g-1.
In order to suppress Zn dendrite formation, the following strategy has been suggested by Parker
et al. [1,2]: (i) facilitating long-range electronic conductivity through the inner core of Zn

2. electrode, (ii) increasing Zn-electrolyte interfaces to distribute current uniformly throughout the
electrode structure, and (iii) forming partially confined void volume elements within the interior
of the porous Zn anode that expedite dissolution/deposition. Parker et al. used sintered Zn
electrode in order to prepare a porous, monolithic, three-dimensional aperiodic architecture;
however, a more ideal architecture can be realized by electroplating Zn onto a three-dimensional
porous current collector such as carbon fiber.
Although I did not teach them the following: the more important strategy is, to optimize the
relation between void-space volume in above-mentioned three-dimensional current collector and
anode/cathode capacity ratio. Dendrite forms, anyway: Li and Zn dissolve into electrolyte
solutions and re-deposit. The strategy is, confine dendrite into the void space in three-
dimensional electrode. One tactic is, to optimize the relation between void-space volume in
above-mentioned three-dimensional current collector and anode/cathode capacity ratio. More
detailed explanation can be, to optimize the void-space volume/re-deposit volume ratio.
Replacing Zn to another material will be another project (my personal future plan 1).
References
[1] J. F. Parker, C. N. Chervin, E. S. Nelson, D. R. Rolison, J. W. Long, Energy Environ. Sci. 7
(2014) 1117-1124.
[2] J. F. Parker, E. S. Nelson, M. D. Wattendorf, C. N. Chervin, J. W. Long, D. R. Rolison, ACS
Appl. Mater. Interfaces 6 (2014) 19471–19476.
2. Development of innovative nonflammable, low cost, and highly durable rechargeable
battery (granted by the Ministry of Education and Science of Kazakhstan)
January 2015 to Present
As the inventor, the initiator, and the Principal Investigator
- Patents = 1 KP applied, 1 PCT applied.
- Publications = 1 oral presentation.
- Supervision: 2 master's degree holders, 2 bachelor's degree holders.
- The uniqueness (novelty) of the battery is realized in combination: (1) a carbon-based porous
current collector such as polyacrylonitrile-based carbon fiber paper or felt having an
electrodeposited anode material, zinc, thereon, thereby forming a porous anode; (2) an
electropolymerized Zn whisker growth suppressor conformally coated onto the Zn anode; (3) a
carbon-based porous current collector such as polyacrylonitrile-based carbon fiber paper or felt
having an impregnated cathode material, LiFePO4, therein, thereby forming a cathode; and (4) an
aqueous (water-based) electrolyte solution including Zn2+ and Li+ ion.
Renewable energy integration into electrical grids is crucial for energy security, leading to the
highly secured communication network, traffic control, industrial activities, etc. However,

3. renewable energies are intermittent and cannot be directly integrated to electric grids without
using batteries. These batteries must be safe and inexpensive from the viewpoint of life-cycle-
cost. Aqueous batteries are non-flammable that can be a great merit compared with traditional
lithium-ion batteries that use flammable organic electrolyte solutions.
Among various types of aqueous rechargeable batteries, Zn/LiFePO4 system is a promising
candidate: it does not use toxic materials unlike lead-acid batteries; it uses the Zn anode that
delivers a higher gravimetric capacity (818 mAh g-1) than metal hydride (e.g.,
LaNi3.55Co0.75Mn0.4Al0.3, 300 mAh g-1 or less) and a comparable potential (-0.76 V vs. Standard
Hydrogen Electrode, SHE) in aqueous media with metal hydride (e.g., LaNi3.55Co0.75Mn0.4Al0.3, -
0.75 to -0.85 V vs. SHE). The problem is Zn dendrite formation resulting in internal short circuit
failure. LiFePO4 can theoretically deliver 170 mAh g-1.
In order to suppress Zn dendrite formation, the following strategy has been suggested by Parker
et al. [1,2]: (i) facilitating long-range electronic conductivity through the inner core of Zn
electrode, (ii) increasing Zn-electrolyte interfaces to distribute current uniformly throughout the
electrode structure, and (iii) forming partially confined void volume elements within the interior
of the porous Zn anode that expedite dissolution/deposition. Parker et al. used sintered Zn
electrode in order to prepare a porous, monolithic, three-dimensional aperiodic architecture;
however, a more ideal architecture can be realized by electroplating Zn onto a three-dimensional
porous current collector such as carbon fiber.
Although I did not teach them the following: the more important strategy is, to optimize the
relation between void-space volume in above-mentioned three-dimensional current collector and
anode/cathode capacity ratio. Dendrite forms, anyway: Li and Zn dissolve into electrolyte
solutions and re-deposit. The strategy is, confine dendrite into the void space in three-
dimensional electrode. One tactic is, to optimize the relation between void-space volume in
above-mentioned three-dimensional current collector and anode/cathode capacity ratio. More
detailed explanation can be, to optimize the void-space volume/re-deposit volume ratio.
References
[1] J. F. Parker, C. N. Chervin, E. S. Nelson, D. R. Rolison, J. W. Long, Energy Environ. Sci. 7
(2014) 1117-1124.
[2] J. F. Parker, E. S. Nelson, M. D. Wattendorf, C. N. Chervin, J. W. Long, D. R. Rolison, ACS
Appl. Mater. Interfaces 6 (2014) 19471–19476.
3. Development of economically feasible three-dimensional lithium/sulfur battery (granted
by the Ministry of Education and Science of Kazakhstan).
January 2015 to Present
As the inventor and the initiator.
- Patents = 1 KP applied, 1 PCT applied.

4. - Supervision = 3 postdoctral researchers, 3 master's degree holders, 4 bachelor's degree holder, 1
student.
- The uniqueness (novelty) of the battery is realized in combination: (1) a metal-based porous
current collector such as Ni foam having an electrodeposited anode material, Sn (can be
intermetallic), thereon, thereby forming a porous anode; (2) an ultrathin separator conformally
coated onto the Sn anode; (3) an impregnated cathode material therein, thereby forming a
cathode; and (4) an aprotic electrolyte solution including Li+ ion.
4. Development of innovative lithium metal-free lithium-ion sulfur battery for renewable
energy, electric transport and electronics (granted by the World Bank and the Government
of the Republic of Kazakhstan)
February 2014 to December 2015.
- Patents: 2 KP applied.
- Publications: 1 paper, 1 conference paper, 1 oral presentation.
- My strategy is as follows: (i) cathode: any sulfur-based cathodes are OK but LiPF6/carbonate-
compatible one that is based on pyrolyzed polyacrylonitrile (PAN) [1] is preferable – patenting
strategy is about hierarchical carbon consisting of PAN and other carbon-based materials, (ii)
anode: starting from graphite for the sake of easy-start, hard carbon (or mesoporous carbon) and
Si are investigated (Si is main but hard carbon is a sort of “insurance”) – anode is pre-lithiated
instead of using explosive Li2S.
Possible further project (or I may have to do this at another place) can include (a) N-
methylpyrrolidone (NMP) elimination from cathode manufacturing process, (b) doubling
electrode thickness without compromising power density, and (c) reducing anode electrolyte
wetting and solid-electrolyte interphase (SEI) layer formation period as Wood et al. [2] have
suggested for cost reduction for conventional lithium-ion batteries based on intercalation
materials. Regarding (a) NMP elimination from cathode manufacturing process, sulfur has a less
positive potential than conventional LiCoO2 etc.; thus, there is no problem. Regarding (b)
doubling electrode thickness without compromising power density, I already reported about
increasing sulfur mass-loading from >> 2 mg cm-2 to 2 - 4 mg cm-2 (roll-press down to 50%
instead of conventional 70 - 80%) [3]: by using high surface area anode materials, anode surface
inactivation becomes less serious than when Li foil is used as an anode as I already implied [3]
and mentioned [4]. Regarding (c) reducing anode electrolyte wetting and solid-electrolyte
interphase (SEI) layer formation period, the pre-lithiation of the anode is a solution, already.
Considering the compatibility with sulfur-based cathode, it may need a further improvement: it
will be another project (a part of my personal future plan 3).
References
[1] J. Wang, J. Yang, J. Xie, N. Xu, Adv. Mater. 14 (2002) 963-965.

5. [2] D. L. Wood III, J. Li, C. Daniel, J. Power Sources 275 (2015) 234-242.
[3] T. Hara, A. Konarov, A. Mentbayeva, I. Kurmanbayeva, Z. Bakenov, Front. Energy Res. 3
(2015) 22.
[4] T. Hara, A. Konarov, A. Mentbayeva, I. Kurmanbayeva, Z. Bakenov, Front. Energy Res. 3
(2015) 22.
5. Flow-free zinc nickel battery. Market and technology analysis. (Nazarbayev University
Graduate School of Business)
October 2015 to November 2015
- Supervision = 4 MBA candidates.
6. Design and engineering of ultimate three-dimensional electrochemical capacitors (3D-
ECC) (Nazarbayev University Capstone Project)
September 2014 to April 2015
- Supervision = 5 bachelor's degree candidates.
- The uniqueness (novelty) of the capacitor is realized by employing a carbon-based porous
current collector such as polyacrylonitrile-based carbon fiber paper or felt having an
electrodeposited cathode material, polyaniline (PANI), thereon, thereby forming a porous
cathode that offers a pseudo capacitance via surface ion adsorption/desorption accompanying
PANI oxidation/reduction. Among many ongoing projects on lithium-ion battery research,
various nano materials have been researched: nano materials have large surface areas and
relatively small bulk volumes; thus, the surface chemistry becomes more dominant than the bulk
one compared with conventional bulky materials. PANI is a well-established typical material that
can be electrochemically active only via surface chemistry; therefore, it offers students a good
opportunity to learn a required concept for understanding the basic concept on ongoing lithium-
ion battery research without challenging any risky non-established chemistry.