The lithium-ion battery has several things that are problematic, we looked at two of them. First it is the chance of a chemical fire, as discussed in the research of the battery. This is dangerous and can create a harmful smoke that is dangerous to people and animals that inhale it. [1] The second thing is the very limited recyclability of the lithium-ion battery. Today less than five percentage of old lithium-ion batteries are recycled [2], but there are companies that try to recycle them to get back or reuse lithium cathodes and cobalt used in the batteries. Cobalt is a resource that is hard to come by and has to be mined as well as lithium [3] and both are a finite resource if they are not recycled. Even tough there are companies that have found recycling methods for certain batteries there is not one standard method of recycling them, this is because the compositions and chemical makeup are different depending on which company has manufactured the batteries. [4] 

Although not inherently hazardous and non-flammable, vanadium may cause eye and respiratory irritation if exposed for an extended period of time. [5] It is possible to recycle vanadium used in VRFB's as a single element is used in the process. The electrolyte can be extracted, filtered and can be re-used. Although the batteries appear to be of low impact, the extraction of the metal must also be considered. Vanadium is a rare metal, which is never found unbound in nature. It occurs in different minerals such as bauxite, vanadinite and carbon containing deposits such as oil shale and tar sands. Although vanadium ores are known, none are mined for this metal specifically. Much of the metal is obtained as a by-product of other ores. [5] One must consider the impact of the processes used to obtain the primary materials in these cases. Extracting the metal from the by-products of combusting fossil fuels would provide a resource from something which would otherwise go to waste. The use of secondary material decreases the environmental impact of the material since the burden is shared with the products which used the material first. [6]

Large scale Ammonia Storage is a new technology in terms of electricity conversion and therefore it is difficult to quantify the environmental impact of installing such a system. However, ammonia is a commonly used chemical for many applications such as fertilisation, cleaning and as a fuel source. [7] However, safety is regarded as a  drawback of using ammonia as a fuel in a fuel cell. Ammonia is considered as a toxic substance but it is detectable by humans in concentrations of just 1 ppm and therefore unlikely to reach dangerous levels unnoticed. Also, due to the lower pressure required to store Ammonia (approx. 10bar) than Hydrogen (approx. 300bar) it is likely that the risk of leakage from a storage tank is far lower for Ammonia than Hydrogen. [8]

Background header: http://www.blue-castle.co.uk/blog/aware-environmental-impact/ 
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5577247/
[2] https://spectrum.ieee.org/energywise/energy/environment/simple-energyefficient-recycling-process-for-lithiumion-cathodes​
[3] ​https://www.marketwatch.com/story/how-lithium-and-cobalt-are-getting-a-boost-from-tesla-apple-batteries-2018-01-29
[4] ​https://www.ft.com/content/c489382e-6b06-11e7-bfeb-33fe0c5b7eaa 
[5] Vanadium (V) - Chemical Properties, Health And Environmental Effects. (2018) Available: https://www.lenntech.com/periodic/elements/v.htm [Accessed: 11 May 2018].
[6] Rydh, C. (2003) Environmental Assessment Of Battery Systems. Göteborg: Chalmers Univ. of Technology, pp.21-29.
[7] https://www.frontiersin.org/articles/10.3389/fenrg.2014.00035/full
​[8] Reich, C. M., Kaiser, A., and Irvine, J. T. S. (2001). Niobia based rutile materials as SOFC anodes. Fuel Cells 1, 249–255. doi:10.1002/1615-6854(200112)1:3/4<249::AID-FUCE249>3.0.CO;2-A