What’s happening next with batteries?
Rarely does a week pass without another news release detailing a breakthrough discovery in battery cell chemistries and the resulting performance leaps it claims. As a battery pack manufacturer this offers the exciting prospect of making packs from new technology cells that would provide a much needed boost to our customers equipment run-time.
Unfortunately the reality tends to be a little less exciting, however battery performance is improving albeit in small steps. Lithium-ion remains the fastest growing cell category in our catalogue of products, and within this group the capacity of an individual cell is increasing. In 2010 our best 18650 sized cell offered 2900mAh of capacity. This cell is commonplace in laptop computers and measures 18mm diameter by 65mm in length. The capacity of this cell increased to 3100mAh in 2011 and further jumped to 3400mAh in late 2012. A 17% increase in capacity over three years is a big deal in the battery world, however this is governed by the volume of the cell container and therefore how much reactive material can fit inside. Unlike the very rapid acceleration in the performance of electronics, roughly a doubling of performance every 18 months, cell performance gains are considerably slower.
Gains in performance of battery powered equipment may be realised by assorted routes to meet increasing expectations of customers.
- Power consumption of the device being powered needs to reduce, likely the quickest gain
- Cell capacity needs to increase for a given volume
- Batteries that can be recharged much faster may solve usability problems
- Energy harvesting should be considered, can energy be gained elsewhere and used to supplement the battery – heat, motion or solar can all be used.
The obvious way to dramatically improve battery performance is to invest heavily in research of the most promising new chemistries. This is happening, both lithium-sulphur and lithium-titanate are promising technologies offering different performance improvements.
- Lithium-sulphur promises more capacity, perhaps three times as much capacity for a given volume of active material, is safer and raw materials more abundant. Challenges exist with making the chemistry stable and reliable.
- Lithium titanate matches current li-ion capacity but has very fast charging capability, around 10 times quicker than normal as well as being rechargeable 1000 times with very little loss of capacity. Both technologies are being tested in real applications and will ultimately come to market if proven successful and reliable.
The need for better battery storage is growing rapidly, electric vehicles and solar energy storage markets are both pushing the development forward both in performance and reducing cost. The key question is when will the major breakthrough happen, something we can’t answer but of course continue to follow developments with interest.