Koch and Archer groups publish on stabilizing battery recharge
Lithium metal anodes are a critical component of next generation battery technologies such as lithium-sulfur and lithium-air, which offer a potentially 4-fold improvement over the state-of-the-art of a fast growing industry, with applications in consumer electronics, electric vehicles and transportation. One of the roadblocks to developing rechargeable lithium metal anodes is the formation of dendrites over the recharge cycle, which can short circuit the battery internally. The present approaches to circumvent this problem involve using intercalation electrodes, which significantly compromise on the battery capacity or employing stiff ceramic membranes to block dendrites, which often suffer from poor conductivity and thus sacrifice battery recharge rates.
Koch and Archer groups have studied the mechanisms leading to dendrite growth for a long time, while looking for practical solutions to mitigating the problem. A recent paper by Mukul Tikekar, a coadvised graduate student in both groups takes a theoretical approach to studying the effect of nanostructured membranes in dendrite suppression. The paper, covered by Cornell Chronicle, shows that immobilizing anions in the membranes forms a second region near the Li metal at high recharge rates, which reduces the charge depletion that is responsible for dendrite formation. This modification to charge transport also helps retain the conductivity at high recharge rates, while acting in conjunction with the elasticity of the membranes to reduce dendrite growth even at moderate, polymer-like moduli.
An important feature of the study is that the model applies to other metals also, including sodium and aluminum. This opens up the possibility of studying an expanded toolset with additional systems to further deepen our understanding of dendrite growth while continuing to look for novel solutions.
Reference: Mukul D Tikekar, Lynden A Archer, & Donald L Koch, (2016) Stabilizing electrodeposition in elastic solid electrolytes containing immobilized anions., Science Advances 2:e1600320