This landscape identifies 581 patent families filed between 2015 and mid-2026 that combine LMO or LiMn2O4 chemistry terms with cycle life, calendar aging, manganese dissolution mitigation or capacity retention language. The bulk sit under IPC class H01M (batteries and cells), with a large secondary group also classified under C01G for inorganic manganese compound chemistry. The oldest and most-cited records in the space, such as US6007947A and US5858573A, date to the mid-to-late 1990s and still get cited in current filings.

The dataset's search terms — manganese dissolution mitigation, calendar aging and capacity retention — map directly onto the known LMO degradation mechanisms that patent claims target: manganese dissolving from the spinel structure at elevated temperature or high state of charge, and gradual structural degradation over repeated cycling. A large share of records (217 of 581) are classified under C01G, indicating that many mitigation approaches work through precursor or particle chemistry rather than through cell control alone.

Assignees with strong historical presence in this corpus include Argonne National Laboratory (in its UChicago Argonne form), Valence Technology, Mitsui Mining & Smelting, LG Chem, LG Energy Solution and CATL-affiliated entities. All of these show zero filings in the most recent year in this dataset, which is best read as a publication-lag effect — publication typically trails filing by around 18 months — rather than as these companies exiting the field.

Filing volume rose from 11 in 2017 to a peak of 29 in 2024, with the 2022 midpoint at 25 — a pattern that looks flat to declining rather than accelerating. That suggests the core mechanisms for extending LMO cycle life and mitigating manganese dissolution are largely staked out, and new filings are increasingly incremental rather than foundational. Readers should still discount the very latest years for publication lag before concluding the field has stalled.

US6392385B1, assigned to Valence Technology, claims a method of cycling a battery containing lithium metal oxide (particularly LMO) active material in a way that reduces capacity loss during use. Because the claim is framed around a charge-discharge control method rather than a specific cell composition, it potentially blocks similar control-based cycling approaches regardless of the exact cathode formulation used. Companies working on LMO durability through materials chemistry rather than charge-control methods face a narrower overlap with this particular claim.