UBC CHEM-E-CAR 2016: ZINC AIR ATTACK Arjun Bhagwat, Ray Bi, Kyle Como, Athanasios Kritharis, Siang Lim, Ngai To Lo, Mani Massah, Andrew MayDepartment Of Chemical and Biological Engineering, The University of British Columbia, Vancouver, BC.UBC Chem-E-Car Engineering Design Team • Email: captain@ubcchemecar.com • Website: www.ubcchemecar.com

[1] J. Helmke, "Gaskatel - BiPlex Gas diffusion electrodes", Gaskatel.de, 2016. Available: www.gaskatel.de/eng/produkte/biplex/eng_biplex_index.html

[2] J. Plachy, "USGS Minerals Information: Zinc", Minerals.usgs.gov, 2016. Available: minerals.usgs.gov/minerals/pubs/commodity/zinc/

A zinc-air battery operates by oxidizing zinc on the anode and reducing oxygen on the cathode. The anodic reaction releases electrons which passes through an external circuit and travels to the cathode, where oxygen is reduced to water in the form of hydroxide ions. Zinc-air cells are no-table for their high theoretical energy density.

The Zinc Air Attack is comprised of an iodine-clock reaction stopping mechanism, a zinc-air power source and an Arduino microcontroller.

POWER SOURCE

INTRODUCTION IODINE CLOCK CALIBRATION CURVE

SAFETY AND ENVIRONMENTAL

REFERENCES

SPONSORS

Manganese Oxide, MnOx Cathode (Gaskatel)

H2O + ZnO + 2OH-Zn+ 4OH- Zn(OH)42-

1/2 O2+ H2OZINC-AIR BATTERY

6M POTASSIUM HYDROXIDE ELECTROLYTE

2e-

2e-

Open Circuit Voltage1.59 V

V ILEDON SEPARATOR

Powdered Zinc AnodeStainless Steel Current Collector

2OH-

V

Reduction

Oxidation

Perimeter assecondary containment

Modular Battery Pack

Fibreglass/Styrofoam Monocoque Body

Modular Circuit DesignIntegrated Water TankFor improved weight distribution

Constructed from scratch

Safety first: spill-proof

Allows single-cell testing

Custom-designed and fabricated electronicsBluetooth data collection system

UNIQUE FEATURES

CONTROL MECHANISM

Arduino

Encoder Wheel

Iodine Clock

Motor

LDR Reading

Servo Actuator

Yes

Speed

Data Transfer to Mobile

(Detachable Module)

SwitchLDR Active?

• Zn is a non-precious metal and is naturally abundant in the environment compared to other elements and MnO2 is environmentally benign • Zn/Air battery by-products, ZnO, is non-toxic, and has many pplications such as: baby powder, ceramics, food additives, etc. • 6 M KOH solution is highly corrosive but it is contained in an anode compartment designed for safe usage• Wire connections are insulated with heat shrink• Gearbox and moving parts are covered with a containment unit• The following MSDS symbols are for those reagents used in both the iodine clock reaction and the Zn/Air battery:

Zinc H2SO4 KOH 3% H2O2 Na2S2O3 KI

Iodine Clock Reaction

I- Oxidation: H2O2 +2I- → I2 +2H2O

I3- Redution: I3

- +2S2O32- → 3I- +S4O6

2

Complex Formation: I3

- + Amylose → Amylose-triiodide complex (color change)

3D Printed Casing

Conductive Plate

Separator

Gaskatel

Air Holes

3D Printed Casing

Zinc Air Cell

Zn/Air Batteries:Anode: SS-116 plate in contact with Zn powder in 6 M KOH to form a paste.-

Cathode: Commercial MnO2/catalyst layer on gold plated nickel mesh (Gaskatel GmbH)

Seperator: Viledon 2227 filter paper manufactured by Freudenberg

Mechanical Body:Fibreglass is a reinforeced plastic made of glass fibres. Fibre layers are set into molds for the desired shape; every layer is rotated to maximize stress distribution.

Circuitry and Electronics:Printed circuit boards (PCBs) were de-signed in EAGLE CAD and fabricated. Additional components were soldered onto the PCB. The encoder wheel allows distance and time data to be collected during the testing phase which is then transmitted and stored wirelessly using Bluetooth.

Colorless Dark Brown

Δt

CONSTRUCTION METHODOLOGY

y = 8.0435x + 15.178R² = 0.9944

y = 4.7893x + 5.8579R² = 0.9697

0

20

40

60

80

100

120

140

160

180

0 2 4 6 8 10 12 14 16 18 20

Time Limit

Volume of Sodium Thiosulfate (mL)

Tim

e N

eede

d Fo

r C

olor

Cha

nge

(s)

0.032g/mL Thiosulfate

0.024g/mL Thiosulfate