Rebecca Ghobrial and Margaret Smith RISKS & ETHICAL ISSUES POSSIBLE NEW ANODES SUSTAINABILITY SOLUTIONS TO RISKS As depicted in the figure, in order for something to be truly “sustainable”, it must incorporate environmental influence, affordability for the average consumer, and effects to the overall standard of living. Refining the current lithium-ion battery has to potential to produce an electric car that it is cheaper, which would address affordability. It would also allow them to compete with the power provided by gas-powered cars, deeming them easier to maintain, which would adhere to customer satisfaction and ultimately standard of living. Because electric cars are not fueled by gasoline, they do not produce the carbon emission that gas powered The most prevalent issue in using lithium as a possible anode is the danger it brings to the battery. When a battery is charging, the anode expands as it absorbs the positive ions from the cathode. However, the lithium in a lithium anode expands irregularly to the point where it can split and crack its protective layer “like paint on the exterior of a balloon that is being inflated." These new cracks provide perfect means for lithium-ions resting on the anode to escape from the once protective layer. When the ions escape, they do so in the form of hair-like structures called dendrites (illustrated in the figure). Each time that a lithium anode battery is recharged, these dendrites increase in size. After just a few charge cycles, they become so large that they can crack the battery casing, which can potentially harm the consumer. In contrast, the increasing growth also has the potential to consume the electrolyte entirely and connect the anode to the cathode. This connection results in the battery short-circuiting itself, which can drastically lower the battery's life span. In comparison, titanium dioxide is the safest material discussed as an anode material. It lacks any fire and reactivity risks, but can offer mild irritation upon contact with skin or eyes. Titanium dioxide is an abundant, cheap, and safe material commonly found in soil. It is frequently used in food as a preservative and in sunscreen in order to absorb ultraviolet waves. When considering building a new battery, it is crucial that the design be safe for the consumer, thus these risks must be addressed with great severity. car do, making them better for the environment. As far as applications for the cell phone, improving the battery would have similar effects as the electric car. Having a more efficient battery for use in cell phones would aid in the already increasing popularity of mobile devices. The proposed solutions would allow cell phone companies to create even newer designs and products to add to the technological productivity of the world today, increasing the standard of living. Also, a more efficient battery would allow users to keep their mobile device for a longer period of time. This increased lifespan means that devices will be disposed of less often, which will have positive effects on the environment and promote sustainability. Apple iPhone Battery -Long time to charge -Charge does not last very long Electric Car Battery -Expensive -Take a long time to charge -Does not allow the driver enough mileage before a recharge -Pose the risk of explosion Creating a protective layer for lithium anodes would solve the issues of dendrite formation and overheating. Stanford Professor Yi Cui created carbon nanospheres, a honeycomb-like microscopic layer which creates a flexible, non-reactive film to prevent the expansion of lithium. This is an ideal solution as this protective layer moves freely up and down as the lithium expands and contacts during the battery’s charge-discharge cycle. Also, these nanospheres do not add any bulk to the battery as they are just 20 nanometers thick, which is about 1/5000 th the width of a human hair. This technology solves a major roadblock with lithium anode batteries and will allow them to be used commercially. Lithium Lithium is an ideal material as an anode as it has high electropositivity and a low density. With lithium anodes, the battery capacity can increase by about four times today’s battery capacity. This translates to a battery that have a lifespan of about 30 hours with moderate to heavy usage. Lithium anode batteries also maintain 99% efficiency after 150 charges which leads to a battery that is more consistent throughout the lifespan of the battery. Titanium Dioxide Batteries with titanium dioxide anodes are a major improvement over today’s batteries as they can charge to 70% in two minutes and fully charge in 5 minutes. These nanotubes are 1/1000 th the size of a strand of hair and have a large surface area of 130 square meters per gram. This large surface area speeds up the chemical reactions that drive the charging and discharging process. Also, the manufacturing of titanium dioxide anodes is a relatively simple process. They are produced via stirring titanium dioxide in with sodium hydroxide under a constant temperature.