Bitrode Testing

The Bitrode Model LCN is a multiple circuit, microprocessor controlled, cycle life tester. Currently this is being used to study the cycle life of different metal hydride electrodes. It is capable of performing standard or fully customized charge and discharge cycles on storage batteries. Each module can be programmed to cycle batteries precisely according to SAE, DIN, BCI, or MIL specification requirements, or to perform reserve capacity and charge acceptance tests. Each module of the LCN system can be programmed and operated independently so that several different types of cycles or tests can be run simultaneously.A module may be programmed to charge or discharge based on constant current, constant voltage, constant power, or any combination of the three.

Tester is equipped with thermocouple probes which may be attached and used to monitor the test cell temperature. The automated cycling system is equipped with a network adapter, thermostat, potentiostat, frequency analyzer, IBM computer and thermocouples in addition to the eight charging and discharging modules. The metal hydride electrodes in our studies are immersed in 6 M KOH in the cells shown on the left. Hg/HgO is used as the reference and Ni plaques are used as the counter electrodes. A constant temperature is maintained in all the cells using a water bath. All the cells are connected in series with the thermostat to the respective modules and the data acquisition is done using a network adapter and IBM PC. The electrochemical tests are carried out every 25th cycle using a EG&G potentiostat and frequency analyzer and the data acquisition is done by an IBM PC. The Bitrode tester is currently used for testing batteries which can withstand currents above 1 mA.

Current research is focussed on developing novel anode and cathode materials for Li-ion batteries. This involves testing materials in very small amounts leading to currents below 1 mA.

T-Cell

This is a typical T-Cell used for our Li-ion studies. T-cell is a three electrode system that is very much useful for performing electrochemical characterization studies on individual electrode materials of Li-ion cell. The positive (LiCoO2 or LiMn2O4) or negative electrode (MCMB carbon) of Li-ion cells will be the working electrode with pure lithium foil being the counter and reference electrodes. The electrolyte used is the Commercial Li-ion battery electrolyte and SS current collectors are used at all the three ends. Either polypropylene sheets or Whatman glass fibre filter can be used as separators between working and counter electrodes. Cyclic voltammetry, Impedance measurements and Intrinsic capacity measurements can be carried out for both positive and negative electrodes of Li-ion cell using this T-cell assembly. T-cells are also proven useful in characterizing different anode and cathode materials synthesized in our labs.

Glove Box

AC Model HE-453-6 Dry-Lab Glovebox, consisting of a 4-station, hermetically sealed glove box enclosure suitable for working with materials sensitive to moisture, oxygen and/or nitrogen. All internal surfaces are constructed of 6061 etched aluminum or Lexan plastic. Access is provided through an evacuable antechamber. Unit is equipped with 8 glove ports, 4 duplex 110V electrical outlets, skylights and vacuum pumps. In addition to this our lab also has a unit of one station with two glove ports.

Model 273A Potentiostat/Galvanostat

The model 273A has the capability to make most of the electrochemical analyses including, cyclic voltammetry, linear scan voltammetry, square wave voltammetry, Chronoamperometry / chronocoulometry, chronopotentiometry, and controlled potential coulometry, etc. It offers either front panel or computer control and is compatible with a wide range of electrode systems.

SI 1255 Frequency Response Analyzer

The 1255 FRA is ideally suited to a wide variety of applications in the fields of electronics and the analysis of electrochemical / biological phenomena. Impedance measurement can provide greater sensitivity and also more information about the processes than conventional dc methods, particularly when impedance's are high or when low conductivity media are being used. High frequency measurements enable the calculation of solution resistance values, thus enabling corrosion resistant materials and polymer coatings (interfacial capacitance's) to be studied. Data can be plotted during the measurement scan, in standard formats such as Bode plots and Complex plane diagrams.

Arbin Instruments

The Arbin is a general-purpose testing instrument equipment for R&D and Quality Check (QC) of any battery, fuell cell or capacitor, including electrode materials. Each channel is a fully functional PST/GST and covers very large current, Voltage and power ranges. Arbin instruments are also very much useful for studying battery packs and charges. Our lab is equiped with 16 channel, 8 channel and a 4 channel charger. In addition to this the lab is also equipped with a new 42 channel BT2000 Arbin charger, with the first 40 channels having a maximum current of 5A and the rest two channels can deliver a maximum DC current of 25A each. The first four channels of the BT2000 charger are equipped with pulse capability (GSM/CDMA pulses as well as user defined pulses).

Miller Gold Star Arc Furnace

Arc Furnace is used to produce special quality steels (steels alloyed with other metals) and some ordinary (non-alloy) quality steels - the lighter long products such as those used for reinforcing concrete. This is a melting furnace in which the charge is heated by an electric arc struck either between an electrode and the charge, or between two electrodes near the charge.

Pellet Compressor (Hot Press)

The Hot Press is mostly used in making Membrane Electrode Unit (MEU) for the low temperature Proton Exchange Membrance Feel Cell (PEMFC). An MEU consists of a cathode, an anode and a membrane. The cathode and the anode are prepared by coating a layer of catalyst (Pt, Ru, Pt-Ru, etc.) over a carbon cloth, which serves as a Gas Diffusion Layer (GDL). Nafion112 is used as a membrane. Now, the anode, the cathode and the membrane need to be pressed together to form a single unit. We use the hot-press for this purpose. The cathode, the anode and the membrane are arranged together with stencils to hold them in place (as shown in the figure). The whole arrangement is placed in a hot-press and is subjected to a pressure of 380 psi and 140°C for 2 minutes. Then the MEU is taken out of the press and is cooled for 10 minutes. The glass-transition temperature of Nafion112 is 140°C and so in this process, the membrane slightly melts and sticks to the electrodes. However, the MEU should not be exposed to higher temperatures for more time since it will destroy the membrane.

Gamry Portable Multistat

Gamry Instruments Portable Electrochemical Test Station allows corrosion testing to be done on locations outside our laboratories. While the Portable Electrochemical Test Station comes as a single package, it has the following components:
1. Potentiostat/Galvanostat/Zero Resistance Ammeter (ZRA) Board Set · 300 mA Potentiostat with PC4 Controller Board and 100 KHz on board FRA · PC4 Cell Cable (1.5 m) & Interconnected Ribbon cable
2. DC105 DC Corrosion Software · Hardware and Software Manuals · Gamry Framework Software (CD-ROM) · One year warranty
The windows based software serves as the interface between the hardware and the computer. This is essential for data acquisition and analysis.
3. EIS300 Electrochemical Impedance Spectroscopy Software (EIS) · Frequency Range from 10 mHz to 100 KHz · EIS300 EIS Experiments
This software allows us to run Impedance Analysis of the concrete rebar. This technique is critical in accurately determining the corrosion rate by deducting the contribution of the solution resistance to the overall cell resistance. Further, impedance analysis also helps us study the role of the passive film formed on the surface in preventing corrosion.
4. Gamry Portable Test Computer (PRISM N8 or Equivalent) · 128 MB Ram, 13 GB Hard Drive, 48X-speed CD-ROM, 1.44 MB Floppy Drive · 12.1” 800X600 TFT Color Display · Detachable Keyboard · Micrsoft Windows 98 and Office 2000 · One year service contract on Gamry Portable Computer
The portable test computer houses the hardware and will be used to carry out the experiments. The Potentiostat/Galvanostat/Zero Resistance Ammeter (ZRA) Board Set is included in the portable computer.

The M-CERT Test System

Materials can be susceptible to environmentally assisted cracking (EAC) in many environments. In some cases, seemingly small changes in process conditions or material processing and fabrication can lead to an unexpected susceptibility to brittle failure caused by SCC, HEC or LEM.
One of the problems in conducting conventional laboratory tests is that the time required to evaluate cracking can take months of exposure. Slow strain rate (SSR) tests (also referred to as constant extension rate tests) can mechanically accelerate testing with the application of a slow constant extension rate. This helps to overcome the initiation process and allows the inherent resistance of the material to be evaluated in a matter of hours or days.
In our lab we have the Constant Extension Rate System (M-CERT)manufactured by Intercorr. This is the next generation in slow strain rate testing capabilities. The computer controlled operation provides for testing over a wide range of testing speeds without the need of cumbersome gear changes. It also has a special anti-backlash feature to allow for cyclic operation.

CERT systems can be programmed to conduct a variety of testing functions that include:

1. Constant extension rate tests.
2. Ramp and hold (constant hold) tests.
3. Cyclic slow strain rate tests.
4. Fracture mechanics tests.

Plating Apparatus

The plating apparatus can be used for D.C. and pulse electrodeposition of a wide range of metals and alloys. The plating tank has the capability to heat the bath for temperatures upto 95oC. Ultrasonic vibrations can be used for agitation of the bath. The plating tank has also the capability to handle various bath sizes for the preparaton of desired sample sizes.

Quantochrome BET Analyzer

Quantochrome NOVA 2000 uses gas sorption techniques to obtain information about the surface area, the porosity of a solid material and the pore size distribution. It is equipped with two independent chambers, one for the sample analysis and one for sample preparation. Two sample ports for each chamber allows preparation and analysis to proceed concurrently without the delay. This is used for the fundamental study of new materials such as supercapacitors and fuel cell electrode.

Tenney Environmental Chamber

Features:-

a) Equipped with a single stage refrigerating system, the controlling range for this chamber is from –40 to +200 degree Celsius with a 6-ft3 capacity.
b) Temperature conditions are accomplished by recirculating chamber air through a refrigerated cooling coil and open-air nichrome wire heater elements. Non-CFC refrigerants are used in the system to ward off hazardous effects. Air circulation is generated by one or more conditioner motors with propeller type fans and they are part of the chamber specification.
c) Additional features such as boost cooling using CO2, boost heating and purge air system using compressed air are accessible in the environmental chamber.
d) Uniform temperature and humidity conditions are assured by the operation of the vertical down recirculating conditioning stream.

Utility of environmental chamber for Li-ion cell-testing:-

a) Since various operating temperatures exist for a battery in real life situation, cell testing has to be performed in different operating temperatures and the performances compared and thus an effective temperature controller is required.
b) The cells have to be tested under a humid-free atmosphere to prevent corrosion possibilities and so the dehumidification operation can be enabled in the chamber by supplying dry air at 80PSIG to 100 PSIGmax.