Hi Bill, Thanks for the references! It makes no sense to expect batteries to charge fast and discharge slowly. Typically the charging is not faster than the discharge. More likely, they are talking about Alu cells available *now* that are 40W per kg versus the newer technology described in the Stanford article that suggests that they can do 4000A per kg, which is presumably 8kW per kg of power density. That factor 200 difference is significant enough that it requires a breakthrough, so apparently it is this breakthrough that Stanford is reporting, compared with earlier Alu technology that has many other drawbacks as well. Time will tell if we soon will have a 1-minute rechargeable battery....
Cor van de Water Chief Scientist Proxim Wireless office +1 408 383 7626 Skype: cor_van_de_water XoIP +31 87 784 1130 private: cvandewater.info www.proxim.com This email message (including any attachments) contains confidential and proprietary information of Proxim Wireless Corporation. If you received this message in error, please delete it and notify the sender. Any unauthorized use, disclosure, distribution, or copying of any part of this message is prohibited. -----Original Message----- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Bill Dennis via EV Sent: Tuesday, April 07, 2015 4:10 PM To: 'Electric Vehicle Discussion List' Subject: Re: [EVDL] Aluminum battery from Stanford Cor wrote: > Who do you trust... http://arstechnica.com/science/2015/04/flexible-aluminum-battery-charges-fas t-stable-for-over-7000-cycles/ -- "But the fact that aluminum atoms only transferred a single electron when they transited to the cathode is really not taking full advantage of the whole reason that people think the material would be good for batteries. And that leads to the low power density of these batteries." http://geniushowto.blogspot.com/2015/04/invented-aluminium-battery-recharges -in-1-minute.html -- "The only disadvantage that these Aluminum ion batteries haven't been able to cover is voltage and power density here it lags behind lithium powered batteries average 4 volts with its 2 volts production and packs a power of 40 watts/kg compared to lithium batteries humongous 206 Watts/kg power density." So I read those numbers in three different articles before posting. But after your Nature reference, I've also now found some articles quoting 3000 W/kg. So it's hard to say which is correct at this point. Note that the arstechnica article referenced above specifically talks about lower power density without using numbers. Is it possible that the cells can be charged much faster than they can be discharged, and the 3000 W/kg number is referring to charge rate, while the 40 W/kg number is discharge rate? Bill _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
