Dendrite-free electrodeposition of lithium metal is necessary for the adoption of high energy-density rechargeable lithium metal batteries. Here, we demonstrate a mechanism of using a liquid crystalline electrolyte to suppress dendrite growth with a lithium metal anode. A nematic liquid crystalline electrolyte modifies the kinetics of electrodeposition by introducing additional overpotential due to its bulk-distortion and anchoring free energy. By extending the phase-field model, we simulate the morphological evolution of the metal anode and explore the role of bulk-distortion and anchoring strengths on the electrodeposition process. We find that adsorption energy of liquid crystalline molecules on a lithium surface can be a good descriptor for the anchoring energy and obtain it using first-principles density functional theory calculations. Unlike other extrinsic mechanisms, we find that liquid crystals with high anchoring strengths can ensure smooth electrodeposition of lithium metal, thus paving the way for practical applications in rechargeable batteries based on metal anodes.

为了采用高能量密度的可充电锂金属电池，锂金属的无枝晶电沉积是必需的。在这里，我们演示了使用液晶电解质抑制锂金属阳极树枝状晶体生长的机理。向列型液晶电解质由于其体积畸变和锚定自由能而引入额外的超电势，从而改变了电沉积的动力学。通过扩展相场模型，我们模拟了金属阳极的形态演变，并探索了体积变形和锚固强度在电沉积过程中的作用。我们发现液晶分子在锂表面上的吸附能可以很好地描述锚固能，并使用第一原理密度泛函理论计算得出。