Air Freight Packing Instruction 965 State of Charge Compliance Verification
Verify air cargo cell charge limits below 30 percent using rested open-circuit voltage lookups or bench discharges backed by signed UN 38.3 test records.
Graphite Delithiation
Meaning
The electrochemical extraction of lithium ions from between the graphene sheets of a carbonaceous anode during battery discharge defines the transition of a cell from a charged state to a depleted state. This reaction occurs as current flow forces lithium to migrate out of the host material and cross the electrolyte to the cathode. The process of graphite delithiation alters the interlayer spacing of the anode, causing a measurable macroscopic volume contraction of the active material.
Phase Transition
Stage transitions in the graphite structure occur sequentially as lithium ions leave the lattice. The progressive graphite delithiation moves through distinct stages of reduced lithium concentration, each corresponding to a specific voltage plateau. These phase changes dictate the electrical potential of the anode relative to the counter electrode.
Rate Limitation
High discharge currents run the risk of causing uneven extraction profile gradients across the electrode thickness. Rapid graphite delithiation can create localized lithium depletion zones, which increase internal resistance and lead to early voltage cutoff under high load conditions.
Degradation Risk
Repeated volume contraction during successive cycles introduces mechanical stress within the composite electrode. When graphite delithiation occurs continuously over hundreds of cycles, the active material can slowly detach from the current collector or fracture the solid electrolyte interphase layer. This physical degradation leads to a permanent loss of capacity.