ZPower's silver-zinc rechargeable batteries promise efficiency gains
By Kyle Sherer
August 6, 2007
August 7, 2007 Even though they are less volatile and more powerful than the alternatives, the price of silver along with some inherent deficiencies has stopped silver-zinc rechargeable batteries from making much of a dent in the market. But by using a unique design incorporating elements of nanotechnology, ZPower silver-zinc batteries could be set to overpower their lithium-ion competitors in every sense of the word. After embracing and improving a neglected model, ZPower now claims its product is more powerful, safer and more environmentally friendly than any other rechargeable battery on the market.
Our appetite for batteries is increasing and the demand for rechargeable batteries is growing twice as fast as the demand for non-rechargeables. Of the rechargeable batteries, lithium-ion is one of the most popular and is frequently used in consumer electronics such as laptops, mobile phones and digital cameras. However, the chemical make up of the battery means that a lot of safeguards are needed to protect against overheating, rupturing and exploding. Silver-zinc batteries on the other hand are water-based, making them chemically safer. ZPower batteries have been subjected to - and survived - a barrage of physical tests including heat, impact, crushing and nail penetration. This stability means that they can safely be taken on airplanes and can be scaled in size without space consuming safeguards.
The energy density of ZPower batteries are 30% greater than lithium-ion types, which means manufacturers who adopt it can allocate the same amount of battery space in a product and receive more battery life, or can allocate a smaller amount of battery space without loss of power. Unlike lithium-ion batteries, which cannot increase power density without sacrificing stability, ZPower believes there is a lot of room for silver-zinc batteries to grow. ZPower batteries can now achieve 200 cycles at 100% discharge and are ahead of schedule to achieve 300 cycles at 100% discharge by 2008.
ZPower batteries also offer environmental advantages. Over 95% of the silver and zinc used in ZPower batteries can be recovered and reused instead of being down-cycled into lower quality materials like lithium-ion batteries, where only the cobalt is able to be fully recycled. The raw materials recovered in the recycling process of silver-zinc batteries are the same quality as those that went into the creation of the battery. This reduces environmental impact by cutting down on the need to mine for new materials and minimizing the depletion of silver and zinc from the earth’s crust.
ZPower has also avoided the deficiencies previously associated with silver-zinc batteries. These include shape change and dendrite growth which are inhibited by a layered separator that effectively stops degradation while allowing ions to pass through unhindered. The internal resistance of the batteries is lowered by a coating of nano particles, enhancing the conductivity of the silver cathode.
High volume production is set to commence next year according to ZPower, but samples of the batteries will be available to select battery dealers later this year for evaluation.