Micro-sized alloying anodes offer lower cost and higher capacity than graphite in Li-ion batteries. However, they suffer from fast capacity decay and low Coulombic efficiency in carbonate electrolytes because the organic solid electrolyte interphase (SEI) strongly bonds to the alloys, leading to cracks of both SEI and alloying particles, which allows electrolyte penetration and forms new SEI during lithiation–delithiation cycles. Using nano-sized alloying anodes can enhance the cell cycle life but also reduces the battery calendar life and increases the manufacturing costs. Here we significantly improved the cycle performance of micro-sized Si, Al, Sn and Bi anodes by developing asymmetric electrolytes (solvent-free ionic liquids and molecular solvent) to form LiF-rich inorganic SEI, enabling 90 mAh μSi||LiNi_0.8Mn_0.1Co_0.1O₂ and 70 mAh Li_3.75Si||SPAN pouch cells (areal capacity of 4.5 mAh cm⁻²; N/P of 1.4) to achieve >400 cycles with a high capacity retention of >85%. The asymmetric electrolyte design forms LiF-rich interphases that enable high-capacity anodes and high-energy cathodes to achieve a long cycle life and provide a general solution for high-energy Li-ion batteries.

与锂离子电池中的石墨相比，微型合金阳极成本更低，容量更高。然而，它们在碳酸盐电解质中面临容量衰减快和库仑效率低的问题，因为有机固体电解质界面（SEI）与合金牢固结合，导致SEI和合金颗粒破裂，从而允许电解质渗透并在锂化过程中形成新的SEI –脱锂循环。使用纳米级合金阳极可以提高电池的循环寿命，但也会缩短电池的日历寿命并增加制造成本。在这里，我们通过开发不对称电解质（无溶剂离子液体和分子溶剂）形成富含LiF的无机SEI，显着提高了微米尺寸Si、Al、Sn和Bi负极的循环性能，从而实现了90 mAh μSi||LiNi _0.8 Mn _0.1 Co _0.1 O ₂和70 mAh Li _3.75 Si||SPAN软包电池（面积容量为4.5 mAh cm ^-2 ；N/P为1.4），以实现>400次循环和>85%的高容量保持率。不对称电解质设计形成富含LiF的界面，使高容量阳极和高能量阴极能够实现长循环寿命，并为高能锂离子电池提供通用解决方案。