V. Focused Fundamental Research - EERE - U.S. Department of ...

V.B.5 The Synthesis and Characterization of Substituted Olivines and
Manganese Oxides (SUNY)
M. Stanley Whittingham (Project Manager)
Binghamton University
Vestal Parkway East
Binghamton, NY 13902-6000
Phone: (607) 777-4623; Fax: (607) 777-4623
E-mail: stanwhit@binghamton.edu
Start Date: June 1, 2007
Projected End Date: December 31, 2011
Objectives
· Find lower-cost and higher-capacity cathodes,
exceeding 200 Ah/kg (700-800 Wh/kg lab
experimental)
· Find high-rate PHEV compatible cathodes
· Both of the above are to be based on
environmentally benign materials.
Technical Barriers
This project addresses the following technical
barriers:
(A) Lower cost materials and processing
(B) Higher power materials
(C) Higher capacity materials
(D) Abuse-tolerant safer cathodes
Technical Targets
· Identify LiNi y Mn y Co 1-2y O 2 systems that can achieve
200 Ah/kg for PHEV applications.
· Identify and evaluate phosphate structures, containing
Fe and/or Mn that have the potential of achieving an
energy density exceeding 700 Wh/kg.
· Identify other materials, including those containing
vanadium, that can undergo more than one electron
transfer per redox center.
Accomplishments
· Shown for the stoichiometric layered oxides that the
composition LiMn 0.4 Ni 0.4 Co 0.2 O 2 is as good
electrochemically as LiMn 0.33 Ni 0.33 Co 0.33 O 2 .
o Lower cobalt contents have higher surface area
and lower cost.
o Capacities over 200 Ah/kg at the C rate in these
Li/M=1 layered oxides will require charging
voltages over 4.4 volts at room temperature (RT).
o In collaboration with NREL showed that these
layered oxides have inherent high rate
capabilities
o Shown that the Li-rich Mn-rich materials have
inferior rate capability than the
LiNi 1/3 Mn 1/3 Co 1/3 O 2 materials at 2C and higher
rates at RT.
o The Li-rich Mn-rich materials have much inferior
thermal stability than materials such as
LiNi 0.4 Mn 0.4 Co 0.2 O 2 . Al substitution helps
increase the thermal stability, but it remains
lower than NMC.
· Identified the pyrophosphates, Li 2 MP 2 O 7 , as candidate
materials that can achieve an energy density
exceeding 700 Wh/kg.
o Li 2 FeP 2 O 7 cycles one lithium readily
o Li 2 MnP 2 O 7 and Li 2 CoP 2 O 7 were inferior
electrochemically.
o Working with Primet, Li 2 FeP 2 O 7 was nanoscissored
and more than one Li was cycled.
o However, severe electrolyte decomposition
occurs.
o Calculations by G. Ceder at MIT concluded
that electrolytes with stabilities over 5 volts
are needed.
· Identified VOPO 4 and VPO 4 , as well as vanadium
oxides as viable candidates for > 1 electron transfer.
· Technology transfer accomplished
o Working with several local battery companies
(Primet on nano-scissored material), and many
ex-students now in battery companies
o Students now have positions at BNL, NREL,
PNNL, Toyota (Ann Arbor), MIT, and Primet
Introduction
Achieving the DOE energy and power targets for
PHEV and EV batteries will require much higher capacity
Energy Storage R&D 488 FY 2011 Annual Progress Report