Overpotential decomposition enabled decoupling of complex kinetic processes in battery electrodes

Revealing the onset condition of Li plating on graphite electrodes under fast-charging

“…Meanwhile, time-resolved potential measurements with an interval of 1 ms are performed on the SLPEs to acquire h gr ct , h gr s , and 1c), in terms of the interfacial Li + intercalation reaction on graphite particles being much slower than the Li metal electrode reaction, electron conduction and SEI lm transport while being much faster than the solid-phase diffusion within graphite layers and lattice phase transition (the detailed methodology can be found in our previous work, ref. 29 ). According to eqn (5) with h l z 0, the Li plating reaction overpotential h gr Li=Li þ on the graphite electrode can be calculated by…”

“…Li plating reaction overpotential) when it becomes negative. 27,28 However, this criterion has not been validated experimentally to date because of two crucial challenges: (a) the Li plating reaction overpotential of graphite electrodes is difficult to be isolated from the coupled overpotentials caused by different polarizations; 1,29 (b) the highly localized Li plating at the separator/electrode interface cannot be sensitively characterized by spatially averaging potential measurements of the whole porous electrode. 11,30,31 The two factors lead to a fuzzy relationship between potential-related information and the onset condition of Li plating.…”

The electrochemical failure mechanism investigation of Li1+xAlxTi2−x(PO4)3 solid-state electrolytes

“…The large median voltage gap reected the severe polarization during cycling. [20][21][22] The results of the chargedischarge proles and median voltage gap curves claried that the bad cycling performance and unstable interface of the LATP pellet could be attributed to the severe polarization.…”

Concentration shift experiment with an electrode of active material for precise electrochemical analysis

“…Composite electrode materials pose various difficulties, not only for the precise electrochemical observation of active materials but also for the correct evaluations of capacity and resistance degradations for LIBs by the inhomogeneous reaction distributions of thickness/ in-plane directions with charge-discharge operations. [10][11][12] Therefore, electrochemical analysis methods for evaluating the charge-discharge behaviour and reactive uniformity of active materials will be critical apart from the electrochemical properties of functional materials to extract the factors governing battery performance.…”