Energy Storage Devices, the real driver behind graphite’s potential;, page-5

I don't want to down-ramp but I won't be expecting li-ion tech to play much of a role in the future static energy storage market. Li-ion excels at energy density hence why it is in our phones, tablets and soonish cars. It is relatively small and importantly light. The compromise is battery life. Currently once a li-ion battery drops to about 86% of capacity, it is effectively at the end of it's life span.

I will use a scenario where you have batteries are connected to your house and will never move (ie: static). 2 issues are less of a concern in this scenario compared to mobile (phones, ev cars etc) scenario's. Weight and volume. If you have a box the size of a refrigerator sitting on a concrete slab next to your hot water system, do you care how much it weighs or if it used a little more space than a li-ion solution? I don't think other battery technologies would use very much more as most space used is for the electronics anyway and both systems would need similar electronics.

Currently a typical li-ion battery has a lifespan between 300 and 500 charge/discharge cycles depending on how it is used and where it is stored. Completely discharge each cycle or store it in a hot place and you will get closer to 300 cycles than 500 out of a battery. The Tesla roadster will stop in standard mode once the battery reached 90% discharge in order to prolong battery life. Compare that to a zinc-bromine flow battery with 2,000 100% charge/discharge cycles and vanadium redox flow batteries (VRB) with 10,000 100% charge/discharge cycles.

Elon Musk hopes to get his li-ion battery costs down to US$300 per kw/hr. Redflow (asx: RFX) states the cost of their zinc bromine flow battery will be US$400 per kw/hr once mass production begins shortly. Sorry I couldn't find a comparable cost for a vanadium redox battery. I am also not sure if a VRB will ever be available at a scale usable in a domestic environment. Also, in the unfortunate event your house catches on fire, a li-ion battery could explode when exposed to the heat and flames.